"Language Server" is written in black, which is barely readable
when the GitHub UI is configured in dark mode.
Switch to gray, which works with in light and dark modes.
* It's fully vectorized now
- replaced the raster logo of Zigtools with an SVG remake
- made it more similar to the one provided by GitHub CI
* Doesn't rely on shields.io anymore
* Left the text as is, without converting it to paths to make editing it easier
* Moved .assets to .github/assets, as they are supposed to be used in web-based
viewers
* Removed images from the project level README file
Utilizes GitHub's features for a special directory ".github". GitHub overrides
the project level README if it finds one in the ".github" directory, allowing to
make a separate READMEs for terminals and the web.
