Add new pinouts for SKY130, IHP SG13G2 and GF180mcuD.
Valid keys for `show_pinouts` can now be easily seen in the `pinout_map` dictionary:
- `caravel`
- `openframe`
- `openframe_sky130`
- `customframe_ihp_sg13g2`
- `customframe_gf180mcud`
The pinout chapter in the datasheet has also been reworked: the content now exists directly in the typst template instead of being an external file. This is to make use of the `pinout_map` and to allow for easier modification of the content.
This change also allows the page to make use of the `callout` function.
This was caused by creating a page before first checking whether there was any content for that page beforehand, so it would result in a rogue white page with no content.
htfab