test(coverage): 100% test coverage & refactor to vitest and msw (#6)

* chore(refactor): tests use vitest and msw
* fix(directory): Ensure filenames conform to eslint requirements
* chore(yarn): Specify node engine version
* fix(yarn): use the proper nodelinker
* fix(GitHub workflow): yarn install with caching
* docs(README): update to match changes

---------

Co-authored-by: Gergő Jedlicska <gergo@jedlicska.com>

.github/workflows/main.yml

@@ -11,6 +11,16 @@ jobs:
     runs-on: ubuntu-latest
     steps:
       - uses: actions/checkout@v3.4.0
+      - name: Get yarn cache directory path
+        id: yarn-cache-dir-path
+        run: echo "dir=$(yarn config get cacheFolder)" >> $GITHUB_OUTPUT
+      - name: Yarn Install
+        run: yarn install
+      - uses: actions/cache/save@v3
+        id: cache-save
+        with:
+          path: ${{ steps.yarn-cache-dir-path.outputs.dir }}
+          key: ${{ runner.os }}-yarn-${{ hashFiles('**/yarn.lock') }}
       - run: |
           yarn run run:mockserver & # run mockserver in background, will be killed when test finishes
       - uses: ./