Add Raigarh Serif typeface

**Font Project Git Repo URL:**
https://github.com/magictype/Raigarh

**Super short description of the Font Family:**
Raigarh — Old-style serif display type for vintage storytelling.

Currently, available in Latin, the font family consists of 5 weights; light, regular, medium, bold and black. It features over 690 precisely crafted glyphs. Includes standard and discretionary ligatures, mathematical features, currency symbols, Arrows, ordinals, accents, Oldstyle figures, Lining figures, Tabular figures, Tabular Oldstyle figures, Fractions, alternative glyphs, and other OpenType features.

Read more about it at [MagicType](https://www.magictype.in/portfolio/raigarh-typeface/)

**Requirements:**

I understand that Google Fonts will publish only fonts that match its requirements, and I can confirm the project meets them (by ticking the cases):

- [x] The entire font project is licensed under the [OFL](https://scripts.sil.org/cms/scripts/page.php?site_id=nrsi&id=OFL)
- [x] Family name is unique according to namecheck.fontdata.com
- [x] If the font targets Latin based written languages, it supports at least [GF Latin Core glyphset](https://github.com/googlefonts/gftools/blob/main/Lib/gftools/encodings/GF%20Glyph%20Sets/GF-latin-core_unique-glyphs.nam)
- [x] I read the [contributing requirements](https://github.com/google/fonts/blob/main/CONTRIBUTING.md)
- [x] The repository respect the [upstream repo structure](https://github.com/googlefonts/gf-docs/tree/main/Spec#upstream-repo-structure)
- [x] I will maintain the repository