* Rename layout macros
The Instant60's info.json was updated in #6157. The intention seems to have been supporting Community Layouts, but that feature was not implemented. After checking that the layouts conform, rename the appropriate layout macros.
- rename LAYOUT_ansi as LAYOUT_60_ansi
- rename LAYOUT_tsangan as LAYOUT_60_tsangan_hhkb
- update `default` and `tsangan` keymaps
* Enable Community Layout support
Supported Community Layouts:
- 60_ansi (Instant60 ANSI version)
- 60_tsangan_hhkb (Instant60 Tsangan version)
