title: Trigger an action for every alphanumeric keypress
body: <p>I have the following lines in a plugin's <code>Default (Windows).sublime-keymap</code> file:</p>
  
  <pre><code>...
  { "keys": ["ctrl+shift+a"], "command": "table_editor_align", "context":
      [
          { "key": "setting.enable_table_editor", "operator": "equal", "operand": true, "match_all": true },
          { "key": "preceding_text", "operator": "regex_contains", "operand": "^\\s*\\|", "match_all": true },
          { "key": "following_text", "operator": "regex_contains", "operand": "$", "match_all": true }
      ]
  },
  ...
  </code></pre>
  
  <p>Instead of triggering this command only when <kbd>ctrl</kbd>+<kbd>shift</kbd>+<kbd>a</kbd>, I'd like to trigger this command <strong>after every alphanumeric keypress</strong> (A-Z, a-z, 0-9, and why not also accents é, à, ç, etc. i.e. all characters that we use while writing)?  </p>
  
  <pre><code>"keys": ["[a-zA-Z0-9_]"]
  </code></pre>
  
  <p>doesn't seem to work.</p>
  
  <p>Note: the plugin is currently a subclass of <a href="http://www.sublimetext.com/docs/3/api_reference.html#sublime_plugin.TextCommand" rel="noreferrer">sublime_plugin.TextCommand</a>, and I think keeping this is mandatory for it to work. The plugin I'm trying to modify is <a href="https://github.com/vkocubinsky/SublimeTableEditor" rel="noreferrer">https://github.com/vkocubinsky/SublimeTableEditor</a>, I would like that auto-re-align is made automatically after each keypress, rather than after each CTRL+SHIFT+A like here:</p>
  
  <p><a href="https://i.stack.imgur.com/H99nX.gif" rel="noreferrer"><img src="https://i.stack.imgur.com/H99nX.gif" alt="enter image description here"></a></p>