docs: maxage/size skeleton

Add skeleton for maxage/maxsize documentation. Also remove the old
nametrans.rst from the old doc location.

Signed-off-by: Sebastian Spaeth <Sebastian@SSpaeth.de>

docs/doc-src/advanced_config.rst

@@ -0,0 +1,16 @@
+Message filtering
+=================
+
+There are two ways to selectively filter messages out of a folder, using `maxsize` and `maxage`. Setting each option will basically ignore all messages that are on the server by pretending they don't exist.
+
+:todo: explain them and give tipps on how to use and not use them. Use cases!
+
+maxage
+------
+
+:todo: !
+
+maxsize
+-------
+
+:todo: !

docs/doc-src/index.rst

@@ -17,8 +17,11 @@ More information on specific topics can be found on the following pages:
 **User documentation**
   * :doc:`Overview and features <features>`
   * :doc:`installation/uninstall <INSTALL>`
+
+**Configuration**
   * :doc:`user manual/Configuration <MANUAL>`
   * :doc:`Folder filtering & name transformation guide <nametrans>`
+  * :doc:`maxage <advanced_config>`
   * :doc:`command line options <offlineimap>`
   * :doc:`Frequently Asked Questions <FAQ>`
 
@@ -34,6 +37,7 @@ More information on specific topics can be found on the following pages:
    INSTALL
    MANUAL
    nametrans
+   advanced_config
    offlineimap
    FAQ