chore: clean up repo - remove broken workflows, update README

- Remove workflows requiring unavailable secrets
- Add simple CI workflow for build and test
- Write clean README with usage examples
- Prepare for dev branch

.github/workflows/ci.yml

@@ -0,0 +1,48 @@
+name: CI
+
+on:
+  push:
+    branches: [master, dev]
+  pull_request:
+    branches: [master]
+
+jobs:
+  build:
+    runs-on: ubuntu-latest
+    steps:
+      - uses: actions/checkout@v4
+
+      - name: Setup Node.js
+        uses: actions/setup-node@v4
+        with:
+          node-version: '20'
+          cache: 'yarn'
+
+      - name: Install dependencies
+        run: yarn install --immutable
+
+      - name: Build JavaScript
+        run: yarn build:js
+
+      - name: Lint
+        run: yarn lint
+
+  test:
+    runs-on: ubuntu-latest
+    steps:
+      - uses: actions/checkout@v4
+
+      - name: Setup Node.js
+        uses: actions/setup-node@v4
+        with:
+          node-version: '20'
+          cache: 'yarn'
+
+      - name: Setup Rust
+        uses: dtolnay/rust-action@stable
+
+      - name: Install dependencies
+        run: yarn install --immutable
+
+      - name: Run Rust tests
+        run: yarn test:wasm-crypto:rust