doc: Add example how to use devenv
Fixes:
@@ -2122,6 +2122,15 @@ the following methods.
...
meson.add_devenv(devenv)
```
+ After configuring and compiling that project, a terminal can be opened with
+ the environment set:
+ ```sh
+ $ meson devenv -C <builddir>
+ $ echo $PLUGINS_PATH
+ /path/to/source/subdir
+ ```
+ See (`meson devenv`)[Commands.md#devenv] command documentation for a list of
+ environment variables that are set by default by Meson.
### `build_machine` object
