theme: add template system (#36)

* user template system

* fix when templates dir doesnt exist

Also color -> colour

---------

Co-authored-by: 2 * r + 2 * t <61896496+soramanew@users.noreply.github.com>

src/caelestia/utils/colour.py

@@ -0,0 +1,28 @@
+class Colour:
+    _rgb_vals: tuple[int, ...]
+    _hex_vals: tuple[str, ...]
+
+    def __init__(self, hex: str):
+        hex = hex.ljust(8, "f")
+        self._hex_vals = tuple(hex[i : i + 2] for i in range(0, 7, 2))
+        self._rgb_vals = tuple(int(h, 16) for h in self._hex_vals)
+
+    @property
+    def hex(self) -> str:
+        return "".join(self._hex_vals[:-1])
+
+    @property
+    def hexalpha(self) -> str:
+        return "".join(self._hex_vals)
+
+    @property
+    def rgb(self) -> str:
+        return f"rgb({','.join(map(str, self._rgb_vals[:-1]))})"
+
+    @property
+    def rgbalpha(self) -> str:
+        return f"rgba({','.join(map(str, self._rgb_vals))})"
+
+
+def get_dynamic_colours(colours: dict[str, str]) -> dict[str, Colour]:
+    return {name: Colour(code) for name, code in colours.items()}