Updated maintainer list and glossary (#359)

Resolves #355.

* Updated maintainers

* Added glossary terms (#355)

* Fixed glossary jump links

* Corrected past maintainer list

* Replaced underscores with hyphens in jump links

README.md

@@ -11,16 +11,14 @@ on how to contribute updates, bug fixes, or other corrections.
 
 ### Current maintainers
 
-- Katy Felkner ([@katyfelkner](https://github.com/katyfelkner))
 - James Foster ([@jd-foster](https://github.com/jd-foster))
-- Sathya Pandalai ([@spandalai](https://github.com/spandalai))
+- Adam Mansur ([@adamancer](https://github.com/adamancer))
 
 ### Past maintainers
 
+- Katy Felkner ([@katyfelkner](https://github.com/katyfelkner))
 - Christina Koch ([@ChristinaLK](https://github.com/ChristinaLK))
+- Paula Andrea Martinez ([@orchid00](https://github.com/orchid00))
 - Timothée Poisot ([@tpoisot](https://github.com/tpoisot))
 - Rémi Rampin ([@remram44](https://github.com/remram44))
 - Ethan White ([@ethanwhite](https://github.com/ethanwhite/))
-- Paula Andrea Martinez ([@orchid00](https://github.com/orchid00))
-
-

learners/reference.md

@@ -1,15 +1,105 @@
 ---
-title: 'FIXME'
+title: Reference
 ---
 
 ## Glossary
 
-## Reference
+*The definitions below are modified from the [Carpentries
+Glosario](https://glosario.carpentries.org/) (CC-BY-4.0)*
+
+[[**aggreation**]{#aggreation}](https://glosario.carpentries.org/en/#aggreation)
+:   To combine many values into one, e.g., by summing a set of numbers.
+
+[[**field**]{#field}](https://glosario.carpentries.org/en/#field)
+:   A component of a [record](#record) containing a single value. Every
+    record in a database [table](#table) has the same fields.
+
+[[**filter**]{#filter}](https://glosario.carpentries.org/en/#filter)
+:   To choose a set of [records](#record) (i.e., rows of a table) based
+    on the values they contain.
+
+[[**full join**]{#full-join}](https://glosario.carpentries.org/en/#full_join)
+:   A [join](#join) that returns all rows and all columns from two
+    tables A and B. Where the [keys](#key) of A and B match, values are
+    combined; where they do not, missing values from either table are
+    filled with [null](#null), NA, or some other [missing
+    value](#missing-value) signifier.
+
+[[**group**]{#group}](https://glosario.carpentries.org/en/#group)
+:   To divide data into subsets according to a set of criteria while
+    leaving records in a single structure.
+
+[[**inner join**]{#inner-join}](https://glosario.carpentries.org/en/#inner_join)
+:   A [join](#join) that returns the combination of rows from two
+    tables, A and B, whose [keys](#key) exist in both tables.
+
+[[**join**]{#join}](https://glosario.carpentries.org/en/#join)
+:   One of several operations that combine values from two
+    [tables](#table).
+
+[[**key**]{#key}](https://glosario.carpentries.org/en/#key)
+:   A [field](#field) or combination of fields whose value(s)
+    uniquely identify a [record](#record) within a [table](#table) or
+    dataset. Keys are often used to select specific records and in
+    [joins](#join).
+
+[[**left join**]{#left-join}](https://glosario.carpentries.org/en/#left_join)
+:   A [join](#join) that combines data from two tables, A and B, where
+    [keys](#key) in table A match keys in table B, [fields](#field) are
+    concatenated. Where a key in table A does *not* match a key in
+    table B, columns from table B are filled with [null](#null), NA, or
+    some other [missing value](#missing-value). Keys from table B that
+    do not match keys from table A are excluded for the result.
+
+[[**missing value**]{#missing-value}](https://glosario.carpentries.org/en/#missing_value)
+:   A special value such as [null](#null) or NA used to indicate the
+    absence of data. Missing values can signal that data was not
+    collected or that the data did not exist in the first place (e.g.,
+    the middle name of someone who does not have one).
+
+[[**null**]{#null}](https://glosario.carpentries.org/en/#null)
+:   A special value used to represent a missing object.
+
+[[**record**]{#record}](https://glosario.carpentries.org/en/#record)
+:   A group of related values that are stored together. A record may be
+    represented as a tuple or as a row in a [table](#table); in the
+    latter case, every record in the table has the same
+    [fields](#field).
+
+[[**relational_database**]{#relational-database}](https://glosario.carpentries.org/en/#relational_database)
+:   A database that organizes information into [tables](#table), each of
+    which has a fixed set of named [fields](#field) (shown as columns)
+    and a variable number of [records](#record) (shown as rows).
+
+[[**right join**]{#right-join}](https://glosario.carpentries.org/en/#right_join)
+:   A [join](#join) that combines data from two tables, A and B. Where
+    [keys](#key) in table A match keys in table B, [fields](#field) are
+    concatenated. Where a key in table B does \*not\* match a key in
+    table A, columns from table A are filled with [null](#null), NA, or
+    some other [missing value](#missing-value) signifier. Keys from
+    table A that do not exist in table B are dropped.
+
+[[**select**]{#select}](https://glosario.carpentries.org/en/#select)
+:   To choose entire columns or rows from a table by name or location.
+
+[[**SQL**]{#SQL}](https://glosario.carpentries.org/en/#sql)
+:   The language used for writing queries for a [relational
+    database](#relational-database). The term is an acronym for
+    Structured Query Language.
+
+[[**table**]{#table}](https://glosario.carpentries.org/en/#table)
+:   A set of [records](#record) in a [relational
+    database](#relational-database) or observations in a data frame.
+    Tables are usually displayed as rows (each of which represents one
+    record or observation) and columns (each of which represents a
+    [field](#field) or variable.)
+
+## Commands
 
 See [this cheat sheet](files/sql-cheat-sheet.md) for an list of the commands
 covered in this lesson.
 
-### Keywords Description Summary
+### Keywords
 
 <table>
     <thead>
@@ -24,12 +114,12 @@ covered in this lesson.
         <tr>
             <td rowspan=3> SELECT </td>
             <td rowspan = 3> Select data from database or table </td>
-            <td> SELECT *</td>
-            <td> Selects the entire dataset</td>
+            <td>SELECT *</td>
+            <td>Selects the entire dataset</td>
         </tr>
         <tr>
             <td>SELECT column1</td>
-            <td> Selects a particular column</td>
+            <td>Selects a particular column</td>
         </tr>
         <tr>
             <td>SELECT 1 + 2</td>
@@ -79,7 +169,7 @@ covered in this lesson.
         </tr>
         <tr>
             <td>JOIN</td>
-            <td> Joins tables</td>
+            <td>Joins tables</td>
             <td>SELECT * <br> FROM surveys <br> JOIN species <br> ON surveys.species_id = species.species_id</td>
             <td>Query will display all the columns from both tables where the condition is met</td>
         </tr>