feat(readme): update key bindings and add functionality details

- add key binding for timeline picker with `<leader>oT`
- include new key binding for browsing code references with `gr`
- clarify command usage for creating and selecting sessions
- touches(config): update default keyboard shortcuts for new features

Author: aweis89

README.md

@@ -350,7 +350,8 @@ The plugin provides the following actions that can be triggered via keymaps, com
 | Close UI windows                                          | `<leader>oq`                          | `:Opencode close`                           | `require('opencode.api').close()`                                      |
 | Select and load session                                   | `<leader>os`                          | `:Opencode session select`                  | `require('opencode.api').select_session()`                             |
 | **Select and load child session**                         | `<leader>oS`                          | `:Opencode session select_child`            | `require('opencode.api').select_child_session()`                       |
-| Open timeline picker (navigate/undo/redo/fork to message) | -                                     | `:Opencode timeline`                        | `require('opencode.api').timeline()`                                   |
+| Open timeline picker (navigate/undo/redo/fork to message) | `<leader>oT`                          | `:Opencode timeline`                        | `require('opencode.api').timeline()`                                   |
+| Browse code references from conversation                  | `gr` (window)                         | `:Opencode references` / `/references`      | `require('opencode.api').references()`                                 |
 | Configure provider and model                              | `<leader>op`                          | `:Opencode configure provider`              | `require('opencode.api').configure_provider()`                         |
 | Open diff view of changes                                 | `<leader>od`                          | `:Opencode diff open`                       | `require('opencode.api').diff_open()`                                  |
 | Navigate to next file diff                                | `<leader>o]`                          | `:Opencode diff next`                       | `require('opencode.api').diff_next()`                                  |

lua/opencode/config.lua

@@ -68,6 +68,7 @@ M.defaults = {
       ['<up>'] = { 'prev_prompt_history', mode = { 'n', 'i' } },
       ['<down>'] = { 'next_prompt_history', mode = { 'n', 'i' } },
       ['<M-m>'] = { 'switch_mode', mode = { 'n', 'i' } },
+      ['gr'] = { 'references', desc = 'Browse code references' },
       ['<leader>oS'] = { 'select_child_session' },
       ['<leader>oD'] = { 'debug_message' },
       ['<leader>oO'] = { 'debug_output' },