General: Add simple contribution guide lines

README now contains simple contribution guide lines that should be
followed. I am now more open for public contributions to the repo
if people are interested.

Create a discord server and link it to the README. Discord seems to be
a nice platform for general messaging.

.pre-commit-config.yaml

@@ -0,0 +1,8 @@
+# .pre-commit-config.yaml
+exclude: '.patch$'
+repos:
+-   repo: https://github.com/pre-commit/pre-commit-hooks
+    rev: v4.1.0  # this is optional, use `pre-commit autoupdate` to get the latest rev!
+    hooks:
+    -   id: end-of-file-fixer
+    -   id: trailing-whitespace