Add a pkgdown documentation site (#78)

You will need to tell GitHub to use the `gh-pages` and the `\` dir to deploy the site (I don't have permission to do that).

Other than that it should just automatically build and deploy the documentation to https://public-health-scotland.github.io/phstemplates/ whenever you add something to main.

.Rbuildignore

@@ -6,3 +6,6 @@
 ^\.github$
 
 ^LICENSE\.md$
+^_pkgdown\.yml$
+^docs$
+^pkgdown$

.github/workflows/pkgdown.yaml

@@ -0,0 +1,48 @@
+# Workflow derived from https://github.com/r-lib/actions/tree/v2/examples
+# Need help debugging build failures? Start at https://github.com/r-lib/actions#where-to-find-help
+on:
+  push:
+    branches: [main, master]
+  pull_request:
+    branches: [main, master]
+  release:
+    types: [published]
+  workflow_dispatch:
+
+name: pkgdown
+
+jobs:
+  pkgdown:
+    runs-on: ubuntu-latest
+    # Only restrict concurrency for non-PR jobs
+    concurrency:
+      group: pkgdown-${{ github.event_name != 'pull_request' || github.run_id }}
+    env:
+      GITHUB_PAT: ${{ secrets.GITHUB_TOKEN }}
+    permissions:
+      contents: write
+    steps:
+      - uses: actions/checkout@v3
+
+      - uses: r-lib/actions/setup-pandoc@v2
+
+      - uses: r-lib/actions/setup-r@v2
+        with:
+          use-public-rspm: true
+
+      - uses: r-lib/actions/setup-r-dependencies@v2
+        with:
+          extra-packages: any::pkgdown, local::.
+          needs: website
+
+      - name: Build site
+        run: pkgdown::build_site_github_pages(new_process = FALSE, install = FALSE)
+        shell: Rscript {0}
+
+      - name: Deploy to GitHub pages 🚀
+        if: github.event_name != 'pull_request'
+        uses: JamesIves/[email protected]
+        with:
+          clean: false
+          branch: gh-pages
+          folder: docs

.gitignore

@@ -23,3 +23,4 @@ data/
 # MacOS folder attributes files #
 .DS_Store
 
+docs

DESCRIPTION

@@ -10,10 +10,11 @@ Authors@R: c(
     person("James", "McMahon", , "[email protected]", role = "ctb",
            comment = c(ORCID = "0000-0002-5380-2029")),
     person("Ellie", "Bates", , "[email protected]", role = "ctb")
-           )
+  )
 Description: Templates for Public Health Scotland.
 License: MIT + file LICENSE
-URL: https://github.com/Public-Health-Scotland/phstemplates
+URL: https://github.com/Public-Health-Scotland/phstemplates,
+    https://public-health-scotland.github.io/phstemplates/
 BugReports: https://github.com/Public-Health-Scotland/phstemplates/issues
 Depends: 
     R (>= 3.2.0)

_pkgdown.yml

@@ -0,0 +1,4 @@
+url: https://public-health-scotland.github.io/phstemplates/
+template:
+  bootstrap: 5
+