Add Picon

**Font Project Git Repo URL:** https://github.com/yne/picon

**Super short description of the Font Family:** Lightweight ligature-based font

**Requirements:**

I understand that Google Fonts will publish only fonts that matches its requirements, and I can confirm the project meets them (by ticking the cases, or putting x between the square brackets in text mode):

- [x] The entire font project is licensed under the [OFL](https://scripts.sil.org/cms/scripts/page.php?site_id=nrsi&id=OFL)
- [x] There is no "Reserved Font Name" mention in the [OFL license](https://github.com/yne/picon/commit/e1cf2f6ff767a59ec6bbd00c1993a72a1d4d42f0)
- [x] Family name is unique according to [namecheck.fontdata.com](https://namecheck.fontdata.com/?q=picon)
- [x] The font supports at least [GF Latin Core glyphset](https://github.com/googlefonts/glyphsets/blob/main/Lib/glyphsets/encodings/GF%20Glyph%20Sets/GF-latin-core_unique-glyphs.nam)
- [ ] The repository respect the [upstream repo structure](https://github.com/googlefonts/gf-docs/tree/main/Spec#upstream-repo-structure) => generated font assets are in [releases](https://github.com/yne/picon/releases), and not in repository itself.
- [x] The source files are available in the repository
- [x] I read, agree and comply with the full [contributing requirements](https://github.com/google/fonts/blob/main/CONTRIBUTING.md)
- [x] I am the author of the font or the author agreed to this submission
- [x] I will maintain the repository

I don't expect this request to be picked, but I'm just following @RosaWagner's https://github.com/google/fonts/pull/2312#issuecomment-1058999624