add theme color ogp tag

[bnidevs]

do .hbs files not allow for a combination of static and dynamic content?

[vcfxb]

No they do, I'm just saying that this breaks the pattern established by the other ogp tags being dynamic, and there should be a comment/justification on why that's the case with this one.

[bnidevs]

This meta tag strictly modifies the color theme of the blocks that are displayed on Discord/elsewhere, and I assumed it could be consistent across all usages of Telescope, unless you want varying colors based on link type?

[vcfxb]

It might be nice to make any telescope link that errors out red, in theory. Although, after further consideration, that would be a bunch of work and a single color across-the-board is probably fine for now. This gets my approval