Hello,

I'm attaching a small patch to add a alt text for the preformatted block
at the start of index.gmi, the one with the `git clone' command.

As things are now, it looks like

	```
	git clone https://example.com/foobar
	```

with the patch

	```Command to clone this repository
	git clone https://example.com/foobar
	```

which is not intrusive and improves the usability of the page IMHO and
the accessibility.

Cheers,

Omar Polo