Add a Gitpod descriptor

.gitpod.yml

@@ -0,0 +1,39 @@
+# List the start up tasks. Learn more https://www.gitpod.io/docs/config-start-tasks/
+tasks:
+  - before: |
+      export GHCUP_INSTALL_BASE_PREFIX=/workspace
+      export BOOTSTRAP_HASKELL_NONINTERACTIVE=1
+      export CABAL_DIR=/workspace/.cabal
+      export STACK_ROOT=/workspace/.stack
+      curl --proto '=https' --tlsv1.2 -sSf https://get-ghcup.haskell.org | sh
+      source /workspace/.ghcup/env
+    init: | 
+      cabal build --enable-tests      
+    command: | 
+      cabal build --enable-tests
+
+# List the ports to expose. Learn more https://www.gitpod.io/docs/config-ports/
+ports: []
+
+github:
+  prebuilds:
+    # enable for the master/default branch (defaults to true)
+    master: true
+    # enable for all branches in this repo (defaults to false)
+    branches: false
+    # enable for pull requests coming from this repo (defaults to true)
+    pullRequests: true
+    # enable for pull requests coming from forks (defaults to false)
+    pullRequestsFromForks: true
+    # add a "Review in Gitpod" button as a comment to pull requests (defaults to true)
+    addComment: false
+    # add a "Review in Gitpod" button to pull requests (defaults to false)
+    addBadge: false
+    # add a label once the prebuild is ready to pull requests (defaults to false)
+    addLabel: prebuilt-in-gitpod
+
+vscode:
+  extensions:
+    - "haskell.haskell"
+    - "justusadam.language-haskell"
+    - "usernamehw.errorlens"