Merge branch 'faqs' into 'master'

add FAQ section

See merge request !62

source/faqs.rst

+FAQs
+====
+
+How can I check whether the database contains enough subjects for my reasearch project?
+---------------------------------------------------------------------------------------
+
+When you :ref:`setup filters for a study <study-recruitment-settings>` you can
+see the number of potential matches in the database. In order to do that you
+first need to :ref:`create a study <study-create>`. It is not a problem if you
+do not yet know the details of the study. Anything you enter can still be
+changed later. You can also delete this study and create a fresh one once you
+are ready.
+
+How can I contact subjects by pseudonym after the study is finished?
+--------------------------------------------------------------------
+
+Finding subjects by pseudonym is no longer possible once the study has
+finished. If you need to contact a subject after the study is finished we
+recommend to :ref:`resume the study <study-finish>` temporarily.

source/index.rst

@@ -13,6 +13,7 @@ Welcome to Castellum's documentation!
    security
    features
    roles
+   faqs
 
 .. toctree::
    :maxdepth: 2