Generated HTML: release links point to 404 pages

I have a set of github packages in my `satis.json` like:
```
"repositories": [
{
"type": "git",
"url": "git@github.com:user/package.git"
},
```
and satis generates a page with Release links like:
```
http://myhomepage.com/git@github.com:user/package.git
```
which is obviously wrong. How to produce correct links?

Start by reproducing the generated page from a satis.json containing the shown git repository entry, then trace how its Release link is assembled. Confirm the current output and determine the correct repository or release URL; done means generated release links no longer point to the malformed path or 404 page.

Written by the indexing model from the issue text.