Document environment variables all in one place

docs/src/SUMMARY.md

@@ -6,9 +6,9 @@
     * [Configuration](./config-file.md)
     * [Reports](./reports.md)
     * [Tags](./tags.md)
+    * [Environment](./environment.md)
     * [Synchronization](./task-sync.md)
   * [Running the Sync Server](./running-sync-server.md)
-  * [Debugging](./debugging.md)
 - [Internal Details](./internals.md)
   * [Data Model](./data-model.md)
     * [Replica Storage](./storage.md)

docs/src/config-file.md

@@ -6,7 +6,7 @@ Configuration is read from `taskchampion.toml` in your config directory.
 On Linux systems, that directory is `~/.config`.
 On OS X, it's `~/Library/Preferences`.
 On Windows, it's `AppData/Roaming` in your home directory.
-This can be overridden by setting `$TASKCHAMPION_CONFIG` to the configuration filename.
+This can be overridden by setting `TASKCHAMPION_CONFIG` to the configuration filename.
 
 The file format is [TOML](https://toml.io/).
 For example:

docs/src/debugging.md

@@ -1,9 +0,0 @@
-# Debugging
-
-Both `ta` and `taskchampion-sync-server` use [env-logger](https://docs.rs/env_logger) and can be configured to log at various levels with the `RUST_LOG` environment variable.
-For example:
-```shell
-$ RUST_LOG=taskchampion=trace ta add foo
-```
-
-The output may provide valuable clues in debugging problems.

docs/src/environment.md

@@ -0,0 +1,21 @@
+# Environment Variables
+
+## Configuration
+
+Set `TASKCHAMPION_CONFIG` to the location of a configuration file in order to override the default location.
+
+## Terminal Output
+
+Taskchampion uses [termcolor](https://github.com/BurntSushi/termcolor) to color its output.
+This library interprets [`TERM` and `NO_COLOR`](https://github.com/BurntSushi/termcolor#automatic-color-selection) to determine how it should behave, when writing to a tty.
+Set `NO_COLOR` to any value to force plain-text output.
+
+## Debugging
+
+Both `ta` and `taskchampion-sync-server` use [env-logger](https://docs.rs/env_logger) and can be configured to log at various levels with the `RUST_LOG` environment variable.
+For example:
+```shell
+$ RUST_LOG=taskchampion=trace ta add foo
+```
+
+The output may provide valuable clues in debugging problems.