docs: Split up 2.0.md and rename to dev_notes.md

Signed-off-by: David Mehren <git@herrmehren.de>

docs/content/dev/dev_notes.md

@@ -0,0 +1,29 @@
+# Development Notes
+This document collects notes and decisions taken during the development of HedgeDoc 2.0.
+It should be converted to a properly structured documentation, but having unstructured docs
+is better than having no docs.
+
+## Supported databases
+We intend to officially support and test these databases:
+
+- SQLite (for development and smaller instances)
+- PostgreSQL
+- MariaDB
+
+## Special Groups
+The software provides two special groups which have no explicit users:
+
+- `everyone` (Describing that everyone who wants to access a note can do if it is enabled in the config.)
+- `loggedIn` (Describing all users which are logged in)
+
+## Entity `create` methods
+
+Because we need to have empty constructors in our entity classes for TypeORM to work, the actual constructor is a separate `create` method. These methods should adhere to these guidelines:
+
+- Only require the non-optional properties of the corresponding entity
+- Have no optional parameters
+- Have no lists which can be empty (so probably most of them)
+- Should either return a complete and fully useable instance or return a Pick/Omit type.
+- Exceptions to these rules are allowed, if they are mentioned in the method documentation
+
+