Documentation and settings improved

docs/source/settings.rst

@@ -0,0 +1,26 @@
+.. _settings:
+
+Settings
+==============
+
+Options are also configurable through settings files. See
+`settings.json <https://github.com/soxoj/maigret/blob/main/maigret/resources/settings.json>`
+for the list of currently supported options.
+
+After start Maigret tries to load configuration from the following sources in exactly the same order:
+
+.. code-block:: console
+
+  # relative path, based on installed package path
+  resources/settings.json
+
+  # absolute path, configuration file in home directory
+  ~/.maigret/settings.json
+
+  # relative path, based on current working directory
+  settings.json
+
+Missing any of these files is not an error.
+If the next settings file contains already known option,
+this option will be rewrited. So it is possible to make
+custom configuration for different users and directories.