docs(readme): improve color palette and installation/usage instructions

Author: PunGrumpy

README.md

@@ -54,7 +54,7 @@ Here is what the improved color palette looks like:
 - [Neovim](https://github.com/neovim/neovim) >=
   [0.7.2](https://github.com/neovim/neovim/releases/tag/v0.7.2)
 
-## 📦 Installation
+## `📦` Installation
 
 Install the theme with your preferred package manager, such as
 [folke/lazy.nvim](https://github.com/folke/lazy.nvim):
@@ -68,7 +68,7 @@ Install the theme with your preferred package manager, such as
 }
 ```
 
-## 🚀 Usage
+## `🚀` Usage
 
 ### Vim Script
 
@@ -119,54 +119,7 @@ require('lualine').setup {
 let g:lightline = {'colorscheme': 'dullahan'}
 ```
 
-## ⚙️ Configuration
-
-> ❗️ Set the configuration **BEFORE** loading the color scheme with `colorscheme dullahan`.
-
-The theme offers four styles: [black](#black) and [white](#white)
-
-[dullahan](https://github.com/PunGrumpy/dullahan.nvim) uses the default options,
-unless `setup` is explicitly called.
-
-```lua
-require("dullahan").setup({
-  -- your configuration comes here
-  -- or leave it empty to use the default settings
-  style = "storm", -- The theme comes in three styles, `black` (default), `gold` and `white`
-  light_style = "white", -- The theme is used when the background is set to light
-  transparent = false, -- Enable this to disable setting the background color
-  terminal_colors = true, -- Configure the colors used when opening a `:terminal` in [Neovim](https://github.com/neovim/neovim)
-  styles = {
-    -- Style to be applied to different syntax groups
-    -- Value is any valid attr-list value for `:help nvim_set_hl`
-    comments = { italic = true },
-    keywords = { italic = true },
-    functions = {},
-    variables = {},
-    -- Background styles. Can be "dark", "transparent" or "normal"
-    sidebars = "dark", -- style for sidebars, see below
-    floats = "dark", -- style for floating windows
-  },
-  sidebars = { "qf", "help" }, -- Set a darker background on sidebar-like windows. For example: `["qf", "vista_kind", "terminal", "packer"]`
-  day_brightness = 0.3, -- Adjusts the brightness of the colors of the **Day** style. Number between 0 and 1, from dull to vibrant colors
-  hide_inactive_statusline = false, -- Enabling this option, will hide inactive statuslines and replace them with a thin border instead. Should work with the standard **StatusLine** and **LuaLine**.
-  dim_inactive = false, -- dims inactive windows
-  lualine_bold = false, -- When `true`, section headers in the lualine theme will be bold
-
-  --- You can override specific color groups to use other groups or a hex color
-  --- function will be called with a ColorScheme table
-  ---@param colors ColorScheme
-  on_colors = function(colors) end,
-
-  --- You can override specific highlights to use other groups or a hex color
-  --- function will be called with a Highlights and ColorScheme table
-  ---@param highlights Highlights
-  ---@param colors ColorScheme
-  on_highlights = function(highlights, colors) end,
-})
-```
-
-## 🪓 Overriding Colors & Highlight Groups
+## `🪓` Overriding Colors & Highlight Groups
 
 How the highlight groups are calculated:
 
@@ -246,20 +199,20 @@ set -as terminal-overrides ',*:Smulx=\E[4::%p1%dm'  # undercurl support
 set -as terminal-overrides ',*:Setulc=\E[58::2::%p1%{65536}%/%d::%p1%{256}%/%{255}%&%d::%p1%{255}%&%d%;m'  # underscore colours - needs tmux-3.0
 ```
 
-## 🔥 Contributing
+## `🔥` Contributing
 
 Pull requests are welcome and encouraged. For major changes, please open an
 issue first to discuss what you would like to change.
 
-## 📖 Changelog
+## `📖` Changelog
 
 See the [CHANGELOG.md](CHANGELOG.md) file for details.
 
-## 📝 License
+## `📝` License
 
 [Affero General Public License v3.0](LICENSE) for more information.
 
-## 🙏 Credits
+## `🙏` Credits
 
 <table>
   <tr>