foreach is now available on Windows

Thanks @rzmk!

Closing #1736

README.md

@@ -48,7 +48,7 @@
 | [fixlengths](/src/cmd/fixlengths.rs#L2) | Force a CSV to have same-length records by either padding or truncating them. |
 | [flatten](/src/cmd/flatten.rs#L2) | A flattened view of CSV records. Useful for viewing one record at a time.<br />e.g. `qsv slice -i 5 data.csv \| qsv flatten`. |
 | [fmt](/src/cmd/fmt.rs#L2) | Reformat a CSV with different delimiters, record terminators or quoting rules. (Supports ASCII delimited data.)  |
-| [foreach](/src/cmd/foreach.rs#L3)<br>✨ | Loop over a CSV to execute shell commands. (not available on Windows)  |
+| [foreach](/src/cmd/foreach.rs#L3)<br>✨ | Loop over a CSV to execute shell commands. |
 | [frequency](/src/cmd/frequency.rs#L2)<br>📇😣🏎️ | Build [frequency tables](https://statisticsbyjim.com/basics/frequency-table/) of each column. Uses multithreading to go faster if an index is present. |
 | [geocode](/src/cmd/geocode.rs#L2)<br>✨🧠🌐🚀🔣 | Geocodes a location against an updatable local copy of the [Geonames](https://www.geonames.org/) cities database. With caching and multi-threading, it geocodes up to 360,000 records/sec! |
 | [headers](/src/cmd/headers.rs#L2)<br>🗄️ | Show the headers of a CSV. Or show the intersection of all headers between many CSV files. |

src/cmd/foreach.rs

@@ -2,7 +2,9 @@ static USAGE: &str = r#"
 Execute a shell command once per line in given CSV file.
 
 NOTE: Windows users are recommended to use Git Bash as their terminal when
-running this command.
+running this command. Download it from https://git-scm.com/downloads. When installing,
+be sure to select "Use Git from the Windows Command Prompt" to ensure that the
+necessary Unix tools are available in the terminal.
 
 WARNING: This command can be dangerous. Be careful when using it with
 untrusted input.