README.md: add install instructions for neovim

README.md

@@ -2,6 +2,42 @@
 
 tree-sitter grammar for [dotenv](https://dotenvx.com)
 
+## Installation
+
+### Neovim
+
+To use this parser in neovim, you need to configure [nvim-treesitter](https://github.com/nvim-treesitter/nvim-treesitter)
+
+Add this to nvim-treesitter's config function:
+
+```lua
+config = function(_, opts)
+    local parser_config = require("nvim-treesitter.parsers").get_parser_configs()
+    
+    -- Tell treesitter where dotenv parser is located
+    parser_config.dotenv = {
+        install_info = {
+            url = "https://github.com/pnx/tree-sitter-dotenv",
+            branch = "main",
+            files = { "src/parser.c", "src/scanner.c" },
+        },
+        filetype = "dotenv",
+    }
+
+    -- Associate .env files as "dotenv"
+    vim.filetype.add({
+        pattern = {
+            ['.env.*'] = 'dotenv',
+        },
+    })
+end
+```
+
+#### Syntax highlighting
+
+In order for neovim to know how to color the text, a `highlights.scm` file is needed.
+Copy [highlights.scm](queries/highlights.scm) from this repo to your nvim config under `queries/dotenv/highlights.scm`
+
 ## Author
 
 Henrik Hautakoski <henrik.hautakoski@gmail.com>