Added documentation about default directories (#5301)

docs/configuration.md

@@ -115,6 +115,34 @@ This also works for secret settings, like credentials:
 export POETRY_HTTP_BASIC_MY_REPOSITORY_PASSWORD=secret
 ```
 
+## Default Directories
+
+Poetry uses the following default directories:
+
+### Config Directory
+
+- Linux: `$XDG_CONFIG_HOME/pypoetry` or `~/.config/pypoetry`
+- Windows: `%APPDATA%\pypoetry`
+- MacOS: `~/Library/Preferences/pypoetry`
+
+You can override the Config directory by setting the `POETRY_CONFIG_DIR` environment variable.
+
+### Data Directory
+
+- Linux: `$XDG_DATA_HOME/pypoetry` or `~/.local/share/pypoetry`
+- Windows: `%APPDATA%\pypoetry`
+- MacOS: `~/Library/Application Support/pypoetry`
+
+You can override the Data directory by setting the `POETRY_DATA_DIR` or `POETRY_HOME` environment variables. If `POETRY_HOME` is set, it will be given higher priority.
+
+### Cache Directory
+
+- Linux: `$XDG_CACHE_HOME/pypoetry` or `~/.cache/pypoetry`
+- Windows: `%APPDATA%\pypoetry\Cache`
+- MacOS: `~/Library/Caches/pypoetry`
+
+You can override the Cache directory by setting the `POETRY_CACHE_DIR` environment variable.
+
 ## Available settings
 
 ### `cache-dir`