Configure CI (#10)

* Create CI.yml

This adds CI using the Set Up OCaml GitHub action.
Handles doc and formatting linting.

* Remove `on: push`

This creates duplicates. `pull_request` is enough.

* Pin ocamlformat's version to make the CI happy

.github/workflows/CI.yml

@@ -0,0 +1,58 @@
+# Based on the example workflow of the Set Up OCaml action
+# <https://github.com/marketplace/actions/set-up-ocaml>
+
+name: CI
+
+on:
+  - pull_request
+
+permissions: read-all
+
+jobs:
+  build:
+    strategy:
+      fail-fast: false
+      matrix:
+        os:
+          - ubuntu-latest
+          - macos-latest
+          - windows-latest
+
+    runs-on: ${{ matrix.os }}
+
+    steps:
+      - name: Checkout tree
+        uses: actions/checkout@v4
+
+      - name: Set-up OCaml
+        uses: ocaml/setup-ocaml@v3
+        with:
+          ocaml-compiler: 5
+
+      - run: opam install . --deps-only --with-test
+
+      - run: opam exec -- dune build
+
+      - run: opam exec -- dune runtest
+
+  lint-doc:
+    runs-on: ubuntu-latest
+    steps:
+      - name: Checkout tree
+        uses: actions/checkout@v4
+      - name: Set-up OCaml
+        uses: ocaml/setup-ocaml@v3
+        with:
+          ocaml-compiler: 5
+      - uses: ocaml/setup-ocaml/lint-doc@v3
+
+  lint-fmt:
+    runs-on: ubuntu-latest
+    steps:
+      - name: Checkout tree
+        uses: actions/checkout@v4
+      - name: Set-up OCaml
+        uses: ocaml/setup-ocaml@v3
+        with:
+          ocaml-compiler: 5
+      - uses: ocaml/setup-ocaml/lint-fmt@v3

.ocamlformat

@@ -1 +1,2 @@
-profile=janestreet
+profile=janestreet
+version=0.27.0