Create Devcontainer config

[garrettw]

As requested by @TimWolla.

[garrettw]

@TimWolla it's all ready for you now

[Girgias]

I don't know anything about containerization and don't have any strong opinions about this.

[TimWolla]

Thank you. I've tried spawning a codespace from your repository, connected to it via VS Code and ran make php. It failed with:

if [ -n "devcontainer" ] && [ "devcontainer" = "devcontainer" ]; then \
        .devcontainer/configure-apache.sh "/workspaces/php-doc-en/output/php-web"; \
fi
Apache web root directory set to /workspaces/php-doc-en/output/php-web
AH00558: apache2: Could not reliably determine the server's fully qualified domain name, using 127.0.0.1. Set the 'ServerName' directive globally to suppress this message
(13)Permission denied: AH00072: make_sock: could not bind to address [::]:80
(13)Permission denied: AH00072: make_sock: could not bind to address 0.0.0.0:80
no listening sockets available, shutting down
AH00015: Unable to open logs
Action 'start' failed.
The Apache error log may have more information.
make: *** [Makefile:29: php] Error 1

It appears the post-create.sh was not properly executed? Do you have any idea of what I did wrong?

Also, I think it would be nice to avoid the additional layer of Docker within a Codespace / dev container. Would it perhaps work to directly install Java + PHP in the Codespace at creation time?

[garrettw]

I'm sure I can find a way to avoid the extra Docker layer. No idea on the other problem though - it's not happening on my end with a fresh Codespace.

[cweiske]

Do I see correctly that devcontainer.json is specific to Visual Studio Code and no other IDEs?

Why is a devcontainer with a web server needed at all, when the Makefile already uses a container to build/render the manual?

[garrettw]

@cweiske The Devcontainer spec is not specific to VS Code, though it was probably implemented there first as it's a Microsoft invention. PhpStorm supports it as well, but more importantly, GitHub Codespaces can use it to spawn a pre-customized browser-based dev environment based on VS Code.

Sorry I've let this languish; life priorities got in the way and it slipped my mind.