Move docs from readme to docs and add a doc build

+ extract docstrings from the public API and get them onto an API
  reference page.

Author: c42f

.github/workflows/CI.yml

@@ -95,18 +95,18 @@ jobs:
             ${{ runner.os }}-
       - uses: julia-actions/julia-buildpkg@v1
       - run: julia sysimage/compile.jl
-#  docs:
-#    name: Documentation
-#    runs-on: ubuntu-latest
-#    steps:
-#      - uses: actions/checkout@v2
-#      - uses: julia-actions/setup-julia@latest
-#        with:
-#          version: '1.6'
-#      - run: julia --project=docs -e '
-#          using Pkg;
-#          Pkg.develop(PackageSpec(; path=pwd()));
-#          Pkg.instantiate();'
-#      - run: julia --project=docs docs/make.jl
-#        env:
-#          GITHUB_TOKEN: ${{ secrets.GITHUB_TOKEN }}
+ docs:
+   name: Documentation
+   runs-on: ubuntu-latest
+   steps:
+     - uses: actions/checkout@v2
+     - uses: julia-actions/setup-julia@latest
+       with:
+         version: '1.9'
+     - run: julia --project=docs -e '
+         using Pkg;
+         Pkg.develop(PackageSpec(; path=pwd()));
+         Pkg.instantiate();'
+     - run: julia --project=docs docs/make.jl
+       env:
+         GITHUB_TOKEN: ${{ secrets.GITHUB_TOKEN }}