[TASK] Adds readme file

README.rst

+==============================================
+Documentation for TYPO3 extension just_sitemap
+==============================================
+
+Installation
+============
+
+Install via composer
+--------------------
+
+.. code-block:: shell
+
+   composer require spooner-web/just_sitemap
+
+Install via Extension Manager
+-----------------------------
+
+1. Open Extension Manager in TYPO3 backend
+2. Search for ``just_sitemap``
+3. Download and install it
+
+Integrators Guide
+=================
+
+Integrate extension
+-------------------
+
+1. Create page for the sitemap
+2. Hide page in menus
+3. Include static template
+4. Add a content element and select ``Google Sitemap``
+5. Select the root page(s) and the recursive level to get all pages
+
+Add doktype to pages not shown
+------------------------------
+
+By default the doktypes ``3,4,6,199,254,255`` are not shown in the sitemap.
+You can add more doktypes, e.g. doktype 12 with:
+
+.. code-block:: typoscript
+
+    plugin.tx_justsitemap.doktypesToIgnore := addToList(12)
+
+
+Enhancing extension
+-------------------
+
+By adding template, partial and layout paths to ``lib.fluidContent`` with their
+subsections ``templateRootPaths``, ``partialRootPaths`` and ``layoutRootPaths`` you can
+create own templates and override the original ones.
+
+To change the markup of the news listing you can add this code into TypoScript:
+
+.. code-block:: typoscript
+
+    lib.fluidContent {
+        templateRootPaths {
+            40 = EXT:my_ext/Resources/Private/Templates
+        }
+        partialRootPaths {
+            40 = EXT:my_ext/Resources/Private/Partials
+        }
+        layoutRootPaths {
+            40 = EXT:my_ext/Resources/Private/Layouts
+        }
+    }
+
+ToDo list
+=========
+
+* Add priority into sitemap (would be best by handling it by the tree level)
+* Add records (like news or other) to the sitemap
+* Add frequency into sitemap (own field in page?)
+
+Contribute
+==========
+
+Feel free to contribute or test the extension!
+Here you can get in contact:
+
+* `GitLab project`_
+* `GitHub project (just a mirror)`_
+* `Slack channel`_
+
+.. _GitLab project: https://git.spooner.io/spooner/just_sitemap
+.. _GitHub project (just a mirror): https://github.com/spoonerWeb/just_sitemap
+.. _Slack channel: https://typo3.slack.com/messages/ext-just_sitemap/