Update docfx-action to 2.8.0 (docfx v2.70.0) (#782)

* Update build process to use latest docfx-action

* Update devcontainer dockerfile to use latest docfx-action

* Add the --open-browser param to the `serve` shortcut command

* Remove devcontainer param

Turns out it doesn't work like we'd expect within a devcontainer. That's fine.

* Add VSCode docker extension to devcontainer

.devcontainer/Dockerfile

@@ -1,4 +1,4 @@
-FROM ghcr.io/nunit/docfx-action:v2.7.0
+FROM ghcr.io/nunit/docfx-action:v2.8.0
 EXPOSE 8080
 
 ### Installing Node LTS into the container

.devcontainer/devcontainer.json

@@ -16,7 +16,8 @@
 				"GitHub.vscode-pull-request-github",
 				"shuworks.vscode-table-formatter",
 				"ms-dotnettools.csharp",
-				"github.vscode-github-actions"
+				"github.vscode-github-actions",
+				"ms-azuretools.vscode-docker"
 			]
 		}
 	}

.github/workflows/build-process.yml

@@ -43,7 +43,7 @@ jobs:
     steps:
       - uses: actions/checkout@v3
         name: Check out the code
-      - uses: "nunit/docfx-action@v2.7.0"
+      - uses: "nunit/docfx-action@v2.8.0"
         name: Build with Docfx
         with:
           args: docs/docfx.json --warningsAsErrors true