feat!: Separate www into www/blog and www/private

Now the private content is stored as a git submodule.
This means I can keep that repo's source private, but still use it in
the build product.
The build product (website) relies on HTTP basic authentication, so
access control is maintained throughout the SDLC.

src/recipes/st-patricks-day/irish-soda-bread-2024.md

@@ -0,0 +1,14 @@
+*Source: Matt*
+
+## Ingredients
+- 170g wholemeal flour
+- 170g plain flour
+- 1/2 tsp salt
+- 1/2 tsp baking soda
+- 290ml buttermilk
+
+## Instructions
+1. Mix together the dry ingredients.
+2. Knead and flatten on a floury surface.
+3. Cut a cross in the top of each loaf.
+4. Bake at 280°C for 30 minutes.