feat: Test running overhaul, switch to Prettier & reformat everything (#1407)

* chore: Switch to Node 20 + Vitest

* chore: migrate to vitest mock functions

* chore: code style (switch to prettier)

* test: re-enable long-running test

Seems the switch to Node 20 and Vitest has vastly improved the code's and / or the test's runtime!

see #1193

* chore: code style

* chore: fix failing tests

* Updated Documentation in README.md

* Update contribution guidelines to state usage of Prettier

* fix: set prettier printWidth back to 80

* chore: apply updated code style automatically

* fix: set prettier line endings to lf again

* chore: apply updated code style automatically

---------

Co-authored-by: github-actions <${GITHUB_ACTOR}@users.noreply.github.com>
Co-authored-by: Lars Müller <34514239+appgurueu@users.noreply.github.com>

Maths/test/Coordinate.test.js

@@ -6,7 +6,12 @@ describe('Testing euclideanDistance calculations', () => {
     expect(euclideanDistance).toBe(15)
   })
   it('Should not give any output given non-numeric argument', () => {
-    const euclideanDistance = coordinate.euclideanDistance('ABC', '123', '', '###')
+    const euclideanDistance = coordinate.euclideanDistance(
+      'ABC',
+      '123',
+      '',
+      '###'
+    )
     expect(euclideanDistance).toBeNaN()
   })
   it('Should not give any output given any number of numeric arguments less than 4', () => {
@@ -27,7 +32,12 @@ describe('Testing manhattanDistance calculations', () => {
     expect(manhattanDistance).toBe(21)
   })
   it('Should not give any output given non-numeric argument', () => {
-    const manhattanDistance = coordinate.manhattanDistance('ABC', '123', '', '###')
+    const manhattanDistance = coordinate.manhattanDistance(
+      'ABC',
+      '123',
+      '',
+      '###'
+    )
     expect(manhattanDistance).toBeNaN()
   })
   it('Should not give any output given any number of numeric arguments less than 4', () => {