feat!: Split site into public and private sections

Moved the Copper Chronicle and resume into a private git submodule
(src/private), visible only to authenticated users. Added a lock symbol
to the mdbook sidebar for restricted sections. Reorganized nginx/nix
configuration files into a dedicated folder. Removed one-line descriptions
from the menu. Reduced custom CSS to better align the main website's theme
with mdbook's native styling. Personalized the index and blog introduction
pages.

src/recipes/misc/README.md

@@ -0,0 +1,28 @@
+# Miscellaneous Recipes
+
+Drinks, snacks, sides, and external links.
+
+## Quick Tips
+
+- Salt garlic before mincing
+- Wet tortillas before frying
+
+## Recipes
+
+- [Balsamic Glazed Brussels Sprouts](balsamic-glazed-brussels-sprouts.md)
+- [Bone Broth](bone-broth.md)
+
+## External Recipe Links
+
+### From Wikibooks Cookbook
+- [Blackberry Oat Bars (Gluten-Free)](https://en.m.wikibooks.org/wiki/Cookbook:Blackberry_Oat_Bars_(Gluten-Free))
+- [Oatmeal Muffins](https://en.m.wikibooks.org/wiki/Cookbook:Oatmeal_Muffins)
+- [Anzac Biscuits I](https://en.m.wikibooks.org/wiki/Cookbook:Anzac_Biscuits_I)
+
+### Other Links
+- [Oatmeal Pancakes](https://based.cooking/oatmeal-pancakes/) (Based Cooking)
+- [Pumpkin Pie from Scratch](https://farmhouseharvest.net/pumpkin-pie-from-scratch/)
+- [Protein Bread](https://theeastcoastkitchen.com/protein-bread/)
+- [Beef Tallow](https://heygrillhey.com/beef-tallow/)
+- [Guide for Substituting Eggs](https://www.kingarthurbaking.com/blog/2021/01/21/guide-for-substituting-eggs-best-egg-replacers)
+- [Backpacker's Shepherd's Pie](https://byucampcooking.blogspot.com/2014/03/backpackers-shepherds-pie.html?m=1)