Add FAQ section to documentation

docs/faq.rst

@@ -0,0 +1,39 @@
+.. _installation:
+
+**************************
+Frequently Asked Questions
+**************************
+
+Overview
+--------
+
+Welcome to the FAQ section! Here, you'll find answers to common questions about TARDIS.
+
+- :ref:`faq-usage`
+
+     - :ref:`faq-usage-memory`
+
+
+.. _faq-usage:
+
+Usage
+-----
+
+.. _faq-usage-memory:
+
+My simulation seems to consume excessive amounts of memory
+^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
+
+
+High memory usage can have many reasons. Both your model
+and certain simulation settings can increase the memory
+usage significantly
+
+1. Enabling ``track_rpacket: true`` will take up substantial
+   amounts of memory, in particular for higher packet counts.
+   Consider turning this feature off or only use it with a
+   small amount of packets.
+2. Both the number of shells and the number of packets
+   increase the memory requirements. Consider using only
+   as many shells/ packets as are required to converge
+   on a result.

docs/index.rst

@@ -59,6 +59,7 @@ Mission Statement
     installation
     quickstart
     tutorials
+    faq
     API <api/modules>