feat(datasheet): automatically determine appropriate pinout table

This is determined by looking at the `pdk` key in the config. If `pdk` doesn't exist, `id` will be used (assuming that the structure of the shuttle ID follows ttX where X=[sky, ihp, gf]). If any part fails, it will fall back to `openframe_sky130`.

The pinout can also be manually controlled by setting the `datasheet_config.pinout` key in the shuttle config, and that will be used verbatim. Note that `datasheet_config.pinout` is not checked, so it *must* be exact, otherwise it will cause the datasheet build to fail.

config.py

@@ -13,7 +13,13 @@ class ArtworkEntryType(TypedDict):
 class DatasheetConfig(TypedDict):
     """TypedDict for the datasheet config within Tiny Tapeout's config.yaml file"""
 
-    pinout: Literal["caravel", "openframe"]
+    pinout: Literal[
+        "caravel",
+        "openframe",
+        "openframe_sky130",
+        "customframe_ihp_sg13g2",
+        "customframe_gf180mcud",
+    ]
     theme_override_colour: str
     show_chip_viewer: bool
     link_disable_colour: bool