Add dark + light svg versions of rust-social-wide

[onefifth]

Matched the font (Fria Sans) from the existing rust-social-wide.jpg

These icons are intended for use in the rust-lang GitHub readme via rust-lang/rust#123093

Closes #1943

[Manishearth]

Seems useful for the rust project.

[Urgau]

Thanks you very much for adding those, I spend way to much time creating one from the JPEG variant.

@onefifth I don't think it's intended but on my system the text is not rendered properly (the font is not right and the text is cut off).

(the text should probably be converted to outlines directly in the svg)

EDIT: just saw the PR on my repo where you mention that it is expected but I still find this unexpected; I would assume that the website would provide images (and SVG) that are ready to be used (and not half-ready/half-unusable); in particular since we don't control where it's going to be used

[onefifth]

@Urgau Huh weird! I was matching the way the esbuild SVG logo you'd referenced handled text.

I'll take a look and update with a converted to path version in a few hours.

My readme pull request won't need updating as the SVG URLs in the readme won't change.

[Urgau]

Inspired by our attempt to make it a SVG. I took a stab at it. That's what I got, it's not perfect but I think it's a good start.

I used the official blank Rust logo: https://github.com/rust-lang/rust-artwork/blob/master/logo/rust-logo-blk.svg
And the Google Font to Svg Path project to create the text outlines.

Settings used in Google Font to Svg Path

Dark variant

[onefifth]

Opened a new issue #1946 and matching PR #1947 with updated SVGs