Recipe book

[melontini]

Hello, this PR is related to #103, but I completely changed the implementation due to a little issue.

I tested it with RBIP (Forge and Fabric) and it works correctly.

The patch is pretty simple, and I also added comments, but as a gist:

• We reset RecipeBookCategories.AGGREGATE_CATEGORIES to vanilla values.
• We inject at the TAIL of RecipeBookManager.init() to merge any categories that may have been added by fabric mods.
• We set RecipeBookCategories.AGGREGATE_CATEGORIES to RecipeBookManager.AGGREGATE_CATEGORIES.

This should account for most additions. Everything else works as is.

[melontini]

Btw, since Forge's event doesn't support modifying existing categories (Unless you do this, lol), it might be better to just insert merged categories at their index.

Actually, it might be better to find the index of the previous group. Something like this:

            //Insert better code here.
            for (int i = 0; i < categories.size(); i++) {
                RecipeBookCategories c = categories.get(i);
                if (eventCategories.contains(c)) continue;

                int realIndex = i;
                if (i > 0) {
                    RecipeBookCategories prev = categories.get(i - 1);
                    int prevIndex = eventCategories.indexOf(prev);
                    if (prevIndex != -1) realIndex = prevIndex + 1;
                }

                if (realIndex >= eventCategories.size()) eventCategories.add(c);
                else eventCategories.add(realIndex, c);
            }

[Su5eD]

I've tested this and it works as expected. Just needs some minor style/structure changes, but otherwise it's good to go.