feat: Add a solarized-dark preset

[CrystalENVT]

chore: Add emacs temp files to gitignore

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[CrystalENVT]

@DeclanChidlow Quick question, I copied the Dracula Preset, & they have a link there that references the color set, so I linked tho the Solarized Dark page. -> https://github.com/revoltchat/themes/blob/master/data/dracula/Preset.toml#L4

Should links not exist at all within the project, or should the link get re-added for a reference standpoint?

I'm okay with whatever answer, just wanting to ask for consistency :)

[DeclanChidlow]

It is my personal opinion that links shouldn't be included as it constitutes some endorsement and increases maintenance burden against link rot.

It is my intention at some point to go through and clean up the metadata of all themes.

[CrystalENVT]

Sure thing :)