Add white stripes to _nobackground logos

[cferenba]

This fixes a longstanding issue with the _nobackground versions of the logo: previously they were missing the white stripes in the speech bubble. This PR adds the stripes.

cc @usrse-maintainers

[cferenba]

Just discovered that this fell through the cracks last year. @USRSE/usrse-maintainers can someone approve?

[cmaimone]

It looks like the font changed when you added the stripes - at least in the github preview

[cferenba]

Hmm, it's rendering with the correct font for me:

I think this is a function of what fonts are available to your web browser.

[cmaimone]

I don't have the same issue with the current image, so something changed. Plus it's still an issue if it shows up in a serif font for me -- we don't want people seeing it that way

[cferenba]

Strange. Let me take a look...

[lparsons]

Just a guess, but perhaps the font used to be embedded, but now it's not?

[cferenba]

@lparsons your guess appears to be correct. In the old file I don't see either the font name or the US-RSE text anywhere, apparently the rendering is already embedded somehow.

[cferenba]

Thinking about it some more: will most people see these .svg files directly, or will they see .png files generated from the .svg's? If the latter, it might not matter whether the .svg's render correctly in github.