Split commit->Message into summary & body as <details>

- Convert newlines to `<br>`s using `nl2br()`
- use `htmlentities()` to convert characters that need to be converted
- Convert `$commit->Message` into an array using `explode()`
- Use `array_shift()` to get the first line for summary
- Use a join on the rest to get commit body
- Commit body becomes the link, summary un-collapses commit

HTML Output:
<details>
<summary>
SUMMARY
</summary>
<a href="URL" target="_blank">
BODY
</a>
</details>