Drewkeys Mercury65 Layout Additions (qmk#21924)

* Rename `LAYOUT` to `LAYOUT_all`

[refactor]

* Add layout/matrix diagram

[docs]

* Correct `LAYOUT_all` data

Correct the order of the Up arrow and End keys.

[enhancement]

* Tidy-up `info.json` formatting

- add line breaks between physical rows
- remove trailing spaces

[style]

* Add `LAYOUT_iso_blocker_split_bs`

[enhancement]

* Add `LAYOUT_iso_blocker_tsangan_split_bs`

[enhancement]

* Add `LAYOUT_ansi_blocker_split_bs`

[enhancement]

* Add `LAYOUT_ansi_blocker_tsangan_split_bs`

[enhancement]