update README

README.md

@@ -8,3 +8,33 @@ Please refer to the [adding parsers](https://github.com/nvim-treesitter/nvim-tre
 
 In order for syntax highlighting to work you copy `queries/highlights.scm` file from this repo to your nvim-treesitter location `queries/dfraw/highlights.scm`.
 More information can be found on the nvim-treesitter page.
+
+Example config:
+```lua
+local parser_config = require'nvim-treesitter.parsers'.get_parser_configs()
+parser_config.dfraw = {
+	install_info = {
+		url = 'https://github.com/JellyApple102/tree-sitter-dfraw',
+		files = { 'src/parser.c' },
+		branch = 'main'
+	},
+	filetype = 'text',
+	used_by = { 'dfraw' }
+}
+```
+Wrap in `lua << EOF` and `EOF` to use in `init.vim`.
+
+By default it is setup to start for any file of type 'text' or 'dfraw'. If you would not like to use it for all text files you can add a custom filetype to neovim.
+Example `.config/nvim/scripts.vim`:
+```vim
+if did_filetype()
+	finish
+endif
+if getline(1) =~# '[a-z_]'
+	setfiletype dfraw
+endif
+```
+This will match any file whose first line is just lowercase letters_and_underscores, and set the filetype to 'dfraw'.
+Than change the config option `filetype = 'dfraw'` and remove the `used_by` option to only use 'dfraw' type files.
+
+More information on custom filetypes [here](https://neovim.io/doc/user/filetype.html#new-filetype).