Include SVG version of MEI logo

[musicEnfanthen]

This PR adds the SVG version of the MEI logo to the repo. (Cudos to @craigsapp for designing it.)

The PR also includes a second version that has been optimized with SVGO to reduce file size (~18kB to ~14 kB) and line numbers (345 to 130) by about 25%.

[musicog]

Thanks!
A couple of points:

1. Should we point to it from somewhere on music-encoding.org, perhaps as a textual link on the main page (e.g., "A vector graphic of the MEI logo is available here" as the last sentence before the sponsors, or as a new page under "Resources")?
2. Particularly if the answer to the above is "yes", can we explicitly associate a CC license with it? Perhaps CC-BY with naming of the "Music Encoding Initiative"? (if this is acceptable to you, @craigsapp!)
   Edit: On reflection CC BY-ND might be preferable? Perhaps something to raise at the next community meeting?

[craigsapp]

Particularly if the answer to the above is "yes", can we explicitly associate a CC license with it? Perhaps CC-BY with naming of the "Music Encoding Initiative"? (if this is acceptable to you, @craigsapp!)
Edit: On reflection CC BY-ND might be preferable? Perhaps something to raise at the next community meeting?

Yes, I transferred it to the MEI entity via an email with Perry Roland (but with the proviso that I can still use it without licensing it :-).

It is probably best to use CC BY-ND so that people do not alter it without permission.

[craigsapp]

Styling it like this variant (homepage of music-encoding):

Should be allowed. Compare to original which is light-themed, three color, with text:

It might be good to provide a set of stylings (dark versus light in this case, for example, or thumbnail versus full size versions).

[musicog]

Agreed that a "dark-mode" SVG should be offered. I can generate one (as SVG) if none exist?
Thumbnail vs full-size is not as relevant in a vector context but we could offer PNGs at different sizes as well...

[rettinghaus]

pinging @musicEnfanthen

[musicog]

Here's versions of the SVG for use on dark backgrounds, using colouring from the logo on music-encoding.org
(I could produce versions with a filled in dark background included, if useful?)

[musicog]

Thanks for the SVGs!
Please consider adding the dark versions as well?
(also, it would be good to link to these from somewhere on the website -- perhaps from the "about" page?)