docs: add lazy.nvim usage (#15)

* docs: add lazy.nvim usage

* docs: clarify pending selection commands

* docs: remove visual default mapping rows

Author: dkarter

README.md

@@ -0,0 +1,140 @@
+# bullets.nvim
+
+Neovim Lua plugin for continuing, renumbering, promoting, demoting, and toggling bullet lists.
+
+## Installation
+
+With [lazy.nvim](https://github.com/folke/lazy.nvim):
+
+```lua
+{
+  "bullets-vim/bullets.nvim",
+  opts = {},
+}
+```
+
+Configure options through `opts`:
+
+```lua
+{
+  "bullets-vim/bullets.nvim",
+  opts = {
+    enabled_file_types = { "markdown", "text", "gitcommit" },
+    mapping_leader = "",
+  },
+}
+```
+
+Without a plugin manager, call setup from Lua:
+
+```lua
+require("bullets").setup({})
+```
+
+Vim is unsupported. Vimscript configuration, including `vim.g.bullets_*` variables, is unsupported.
+Configure this plugin only with `require("bullets").setup({})` or lazy.nvim `opts`.
+
+## Options
+
+Defaults from `lua/bullets/config.lua`:
+
+```lua
+{
+  enabled_file_types = { "markdown", "text", "gitcommit" },
+  enable_in_empty_buffers = false,
+  set_mappings = true,
+  mapping_leader = "",
+  custom_mappings = {},
+  delete_last_bullet_if_empty = 1,
+  line_spacing = 1,
+  pad_right = true,
+  max_alpha_characters = 2,
+  enable_roman_list = true,
+  list_item_styles = { "-", "*+", ".+", "#.", "+", "\\item" },
+  outline_levels = { "ROM", "ABC", "num", "abc", "rom", "std-", "std*", "std+" },
+  renumber_on_change = true,
+  nested_checkboxes = true,
+  enable_wrapped_lines = true,
+  checkbox_markers = " .oOX",
+  checkbox_partials_toggle = 1,
+  auto_indent_after_colon = true,
+}
+```
+
+`custom_mappings` entries are passed to `vim.keymap.set` as `{ mode, lhs, rhs }` for each configured buffer.
+
+## Commands
+
+The plugin defines these commands:
+
+| Command                | Action                                   |
+| ---------------------- | ---------------------------------------- |
+| `:InsertNewBullet`     | Insert a continued list item.            |
+| `:RenumberList`        | Renumber the current list.               |
+| `:RenumberSelection`   | Renumber the selected range.             |
+| `:ToggleCheckbox`      | Toggle the checkbox on the current item. |
+| `:RecomputeCheckboxes` | Recompute nested checkbox states.        |
+| `:BulletDemote`        | Demote the current item.                 |
+| `:BulletPromote`       | Promote the current item.                |
+| `:BulletDemoteVisual`  | Demote the selected range.               |
+| `:BulletPromoteVisual` | Promote the selected range.              |
+
+These selection commands are registered but not implemented yet: `:SelectCheckbox`,
+`:SelectCheckboxInside`, `:SelectBullet`, and `:SelectBulletText`.
+
+## Mappings
+
+Default mappings are buffer-local for `enabled_file_types` when `set_mappings = true`.
+Each left-hand side is prefixed with `mapping_leader`, which defaults to an empty string.
+
+| Mode   | Mapping     | Action                                   |
+| ------ | ----------- | ---------------------------------------- |
+| Insert | `<CR>`      | Insert a continued list item.            |
+| Insert | `<C-CR>`    | Insert a plain newline.                  |
+| Normal | `o`         | Insert a continued list item.            |
+| Normal | `gN`        | Renumber the current list.               |
+| Visual | `gN`        | Renumber the selected range.             |
+| Normal | `<leader>x` | Toggle the checkbox on the current item. |
+| Insert | `<C-t>`     | Demote the current item.                 |
+| Normal | `>>`        | Demote the current item.                 |
+| Insert | `<C-d>`     | Promote the current item.                |
+| Normal | `<<`        | Promote the current item.                |
+
+The plugin also defines these `<Plug>` mappings for custom mappings:
+
+| Mapping                                | Modes                  |
+| -------------------------------------- | ---------------------- |
+| `<Plug>(bullets-newline)`              | Insert, Normal         |
+| `<Plug>(bullets-renumber)`             | Normal, Visual         |
+| `<Plug>(bullets-toggle-checkbox)`      | Normal                 |
+| `<Plug>(bullets-recompute-checkboxes)` | Normal                 |
+| `<Plug>(bullets-demote)`               | Insert, Normal, Visual |
+| `<Plug>(bullets-promote)`              | Insert, Normal, Visual |
+
+## Development
+
+Install tools with mise:
+
+```sh
+mise install
+```
+
+Format files:
+
+```sh
+mise run fmt
+```
+
+Check formatting:
+
+```sh
+mise run fmt:check
+```
+
+Run tests:
+
+```sh
+mise run test
+```
+
+The test task runs each `test/*_spec.lua` file in headless Neovim with plenary.