feat: move towards individual folder manifests

[afonsojramos]

Welcome to PR number #766, this will be a big one, so bear with me.

This is something that I've thought about for quite a while and I think it is time that we move towards a centralised manifest point of view. That is, having a manifest in spicetify-themes that holds a readme with images to all themes + themes manifest. We then generate the "master" manifest with all the themes that are present. Think of it as the official DB for Marketplace.

In the end, we will have more granular control of what we display to end-users. And developers will continue to have all of the freedom to develop their themes and extensions within their repositories. In the end, the only change will be that the manifests that are present in the developers repo's will move to this repo.

This PR mostly attempts to fix spicetify/marketplace#111, however, it also ends up fixing spicetify/marketplace#137.

Once this PR is ready for primetime we will have a period where theme developers will be able to create PRs so that when we make the switch from github topics to master manifest every theme you love is present!

Additionally, I've added an image compression action so that the images we upload here do not occupy as much space.

[github-actions]

Images automagically compressed by Calibre's image-actions ✨

Compression reduced images by 16.5%, saving 4.54 MB.

Filename	Before	After	Improvement	Visual comparison
.extra/SpotifyNoControl/windows-shortcut-instruction.png	10.35 KB	9.83 KB	-5.0%	View diff
Dreary/screenshots/bib.png	891.98 KB	758.62 KB	-15.0%	View diff
Dreary/screenshots/deeper.png	983.89 KB	847.71 KB	-13.8%	View diff
Dreary/screenshots/golden.png	846.57 KB	676.95 KB	-20.0%	View diff
Dreary/screenshots/graytone-blue.png	583.06 KB	425.00 KB	-27.1%	View diff
Dreary/screenshots/mono.png	950.28 KB	837.59 KB	-11.9%	View diff
Dreary/screenshots/psycho.png	850.16 KB	734.23 KB	-13.6%	View diff
Dribbblish/screenshots/samourai.png	168.71 KB	166.86 KB	-1.1%	View diff
Dribbblish/screenshots/white.png	135.90 KB	133.20 KB	-2.0%	View diff
Dribbblish/windows-shortcut-instruction.png	10.35 KB	9.83 KB	-5.0%	View diff
Flow/screenshots/ocean.png	2.21 MB	1.95 MB	-11.9%	View diff
Flow/screenshots/pink.png	2.18 MB	1.93 MB	-11.5%	View diff
Flow/screenshots/silver.png	2.11 MB	1.89 MB	-10.7%	View diff
Flow/screenshots/violet.png	2.22 MB	1.95 MB	-11.8%	View diff
Glaze/screenshots/base.png	887.30 KB	722.05 KB	-18.6%	View diff
Glaze/screenshots/dark.png	939.83 KB	757.11 KB	-19.4%	View diff
Glaze/screenshots/gray.png	879.92 KB	740.26 KB	-15.9%	View diff
Sleek/screenshots/psycho.png	401.17 KB	357.72 KB	-10.8%	View diff
Sleek/screenshots/vantablack.png	680.59 KB	665.32 KB	-2.2%	View diff
Sleek/screenshots/wealthy.png	482.34 KB	462.70 KB	-4.1%	View diff
Turntable/screenshots/blur_fad_vertical.png	1.56 MB	1.12 MB	-28.0%	View diff
Turntable/screenshots/blur_fad.png	1.51 MB	1.09 MB	-27.6%	View diff
Turntable/screenshots/fad_vertical.png	1.25 MB	979.08 KB	-23.3%	View diff
Turntable/screenshots/fad.png	1.21 MB	957.89 KB	-22.8%	View diff
Turntable/screenshots/turntable.png	1.12 MB	934.96 KB	-18.7%	View diff
Ziro/screenshots/album-blue-dark.png	263.03 KB	253.89 KB	-3.5%	View diff
Ziro/screenshots/cards-gray-dark.png	325.35 KB	297.71 KB	-8.5%	View diff
Ziro/screenshots/podcast-green-dark.png	242.24 KB	185.06 KB	-23.6%	View diff
Ziro/screenshots/podcast-green-light.png	422.13 KB	414.20 KB	-1.9%	View diff
Ziro/screenshots/profile-red-dark.png	196.41 KB	183.13 KB	-6.8%	View diff
Ziro/screenshots/queue-red-light.png	218.31 KB	194.49 KB	-10.9%	View diff
Ziro/screenshots/rose-pine-dawn.jpg	351.00 KB	138.99 KB	-60.4%	View diff
Ziro/screenshots/rose-pine-moon.jpg	344.12 KB	140.78 KB	-59.1%	View diff
Ziro/screenshots/search-orange-dark.png	424.79 KB	420.18 KB	-1.1%	View diff

35 images did not require optimisation.

[github-actions]

Images automagically compressed by Calibre's image-actions ✨

Compression reduced images by 4.6%, saving 49.50 KB.

Filename	Before	After	Improvement	Visual comparison
Nord/screenshots/screenshot_1.png	769.70 KB	738.11 KB	-4.1%	View diff
Nord/screenshots/screenshot_2.png	305.28 KB	287.37 KB	-5.9%	View diff

69 images did not require optimisation.

[kyrie25]

@kyrie25 although I appreciate you trying to help, I'd like to understand your changes. Why did you manually edit manifest.json, and why did you remove Bloom? Was it because of the conflicts?

Yes, it was because of the conflicts as Bloom itself was removed quite some time in main itself

Also, the invalid character started after some of your changes, why the need for all of these commits?

The invalid character appeared on my very first commit to this branch of what appears to be a CI problem where it'd remove the whitespaces from the echo command and the following was me trying to figure out why as I did not change any part of the .yml file. You can check the CI run on my first commit to this branch to see what I was addressing to.

[harbassan]

Still happening? @afonsojramos

[CharlieS1103]

@OverRevvv I don't know why you're approving this, it's not even close to ready yet?