Add some brief text at the start of each section

docs/source/reference/index.md

@@ -2,12 +2,17 @@
 
 ## `dsh` command line interface
 
+The `dsh` commands are the entrypoint to the Data Safe Haven command line interface.
+All commands begin with `dsh`.
+
 :::{typer} data_safe_haven.commands.cli:application
 :prog: dsh
 :width: 65
 :::
 
-## Config commands
+## `config` commands
+
+`config` commands are used to manage the configuration files that define SHMs and SREs.
 
 :::{typer} data_safe_haven.commands.config:config_command_group
 :width: 65
@@ -16,7 +21,9 @@
 :make-sections:
 :::
 
-## Context commands
+## `context` commands
+
+`context` commands are used to manage the Data Safe Haven contexts, which are the grouping within which a single SHM and its associated SREs are organised.
 
 :::{typer} data_safe_haven.commands.context:context_command_group
 :width: 65
@@ -25,7 +32,9 @@
 :make-sections:
 :::
 
-## SHM commands
+## `shm` commands
+
+`shm` commands are used to deploy or teardown DSH Safe Haven Management infrastructure
 
 :::{typer} data_safe_haven.commands.shm:shm_command_group
 :width: 65
@@ -34,7 +43,9 @@
 :make-sections:
 :::
 
-## SRE commands
+## `sre` commands
+
+`sre` commands are used to deploy or teardown the infrastructure for DSH Secure Research Environments
 
 :::{typer} data_safe_haven.commands.sre:sre_command_group
 :width: 65
@@ -43,7 +54,9 @@
 :make-sections:
 :::
 
-## User commands
+## `users` commands
+
+`users` commands are used to manage users on the Entra ID associated with a DSH deployment.
 
 :::{typer} data_safe_haven.commands.users:users_command_group
 :width: 65
@@ -52,7 +65,7 @@
 :make-sections:
 :::
 
-## Pulumi commands
+## `pulumi` commands
 
 :::{typer} data_safe_haven.commands.pulumi:pulumi_command_group
 :width: 65