doc: hooks and overwriting hi groups

README.md

@@ -282,6 +282,8 @@ colorscheme catppuccin
 vim.cmd[[colorscheme catppuccin]]
 ```
 
+### Extra
+
 #### API
 
 The API allows you fetch data from Catppuccin. It can be required as a Lua module:
@@ -300,6 +302,40 @@ cp_api.get_colors()
 
 > Returns a table where the key is the name of the color and the value is its hex value.
 
+#### Overwriting highlight groups
+
+Both colors and highlight groups can be overwritten like so:
+
+```lua
+catppuccin.remap({ <hi_group> = { <fields> }, })
+```
+
+Here is an example:
+
+```lua
+local colors = require'catppuccin.api.colors'.get_colors() -- fetch colors with API
+catppuccin.remap({ Comment = { fg = colors.catppuccin2 }, })
+```
+
+#### Hooks
+
+Use them to execute code at certain events. These are the ones available:
+
+| Function           | Description                  |
+| ------------------ | ---------------------------- |
+| `before_loading()` | Before loading a colorscheme |
+| `after_loading()`  | After loading a colorscheme  |
+
+They can be used like so:
+
+```lua
+local catppuccin = require("catppuccin")
+
+catppuccino.before_loading = function ()
+	print("I ran before loading Catppuccin!")
+end
+```
+
 ### Configuration
 
 Although settings already have self-explanatory names, here is where you can find info about each one of them and their classifications!