feat: setup monorepo using pnpm (#20)

* tests: fix float problems and PAT problem

* extend CONTRIBUTING.md

* extend build documentation, add GH action, fix build on MacOS

* fix build on Vercel

* update .gitignore and CONTRIBUTING.md

* feat: begin work on monorepo

* chore(actions/basic-build): use pnpm

* fix: vercel-deploy

* docs: updates with new folders

* chore: apply PR review comments

---------

Co-authored-by: martin-mfg <2026226+martin-mfg@users.noreply.github.com>

.github/workflows/basic-build.yml

@@ -0,0 +1,31 @@
+name: Basic Build
+
+on:
+  workflow_dispatch: # Allows you to run this manually from the Actions tab
+  push:
+  pull_request:
+
+jobs:
+  build-and-test:
+    name: Build and test on ${{ matrix.os }}
+
+    strategy:
+      fail-fast: false
+      matrix:
+        os: [ubuntu-latest, macos-latest]
+    runs-on: ${{ matrix.os }}
+
+    steps:
+      - name: Checkout code
+        uses: actions/checkout@v6
+
+      - name: Install Dependencies
+        uses: ./.github/actions/install-dependencies
+
+      - name: Run vercel-preparation.sh
+        run: |
+          chmod +x ./vercel-preparation.sh
+          ./vercel-preparation.sh
+
+      - name: Build frontend
+        run: pnpm --filter frontend run build-trends