document files, paths and environment variables

docs/source/index.rst

@@ -716,12 +716,43 @@ Day of the week that should be considered as the start for :ref:`t-week`.
 Options are ``"monday"``, ``"tuesday"``, ``"wednesday"``, ``"thursday"``,
 ``"friday"``, ``"saturday"``, ``"sunday"``.
 
-Files and paths
----------------
+Files, paths and the environment
+--------------------------------
 
-.. note::
+Tiempo uses the same directory to store the database and configuration. It's
+location depends on the operative system, but it's likely one of these options:
 
-   explain the config file, database path and environment variables
+**On Linux**
+
+tiempo respects ``XDG`` variables. So most likely the config directory is
+``$HOME/.config/tiempo``.
+
+**On windows**
+
+``{FOLDERID_RoamingAppData}``
+
+**On mac**
+
+``$HOME/Library/Application Support``
+
+To be 100% sure run ``t c``.
+
+Inside the config directory you'll find two files: ``config.toml`` and
+``database.sqlite3`` which are your settings file and database respectively.
+
+Tiempo also recognises traditional ``timetrap`` config and directories, which in
+all platforms should be: ``$HOME/.timetrap.yml`` for the config file and
+``$HOME/.timetrap.db`` for the database.
+
+You can set the config file to a different location by setting the
+``TIMETRAP_CONFIG_FILE`` envornment variable to an absolute path that includes
+the filename like so:
+
+
+``TIMETRAP_CONFIG_FILE=/home/user/some/dir/my_config.toml``
+
+From within the config file you can set the paths to the database and custom
+formatters as explained in the :ref:`settings`.
 
 .. _specifying-times: