Add linting step to github actions

.github/workflows/lint.yaml

@@ -0,0 +1,74 @@
+name: Lint
+
+on:
+    push:
+        branches:
+            - master
+    pull_request:
+        branches:
+            - master
+
+jobs:
+    lint-js:
+        name: Lint JS/TS
+        runs-on: ubuntu-latest
+
+        steps:
+            - name: Checkout
+              uses: actions/checkout@v2
+
+            - name: Setup node env
+              uses: actions/[email protected]
+              with:
+                  node-version: 14
+
+            - name: Get yarn cache directory path
+              id: yarn-cache-dir-path
+              run: echo "::set-output name=dir::$(yarn cache dir)"
+
+            - name: Cache node_modules
+              uses: actions/cache@v2
+              id: yarn-cache # use this to check for `cache-hit` (`steps.yarn-cache.outputs.cache-hit != 'true'`)
+              with:
+                  path: ${{ steps.yarn-cache-dir-path.outputs.dir }}
+                  key: ${{ runner.os }}-yarn-${{ hashFiles('**/yarn.lock') }}
+                  restore-keys: |
+                      ${{ runner.os }}-yarn-
+
+            - name: Install dependencies
+              run: yarn install --frozen-lockfile
+
+            - name: Run ESLint
+              run: yarn run lint:js
+
+    lint-css:
+        name: Lint CSS
+        runs-on: ubuntu-latest
+
+        steps:
+            - name: Checkout
+              uses: actions/checkout@v2
+
+            - name: Setup node env
+              uses: actions/[email protected]
+              with:
+                  node-version: 14
+
+            - name: Get yarn cache directory path
+              id: yarn-cache-dir-path
+              run: echo "::set-output name=dir::$(yarn cache dir)"
+
+            - name: Cache node_modules
+              uses: actions/cache@v2
+              id: yarn-cache # use this to check for `cache-hit` (`steps.yarn-cache.outputs.cache-hit != 'true'`)
+              with:
+                  path: ${{ steps.yarn-cache-dir-path.outputs.dir }}
+                  key: ${{ runner.os }}-yarn-${{ hashFiles('**/yarn.lock') }}
+                  restore-keys: |
+                      ${{ runner.os }}-yarn-
+
+            - name: Install dependencies
+              run: yarn install --frozen-lockfile
+
+            - name: Run stylelint
+              run: yarn run lint:css