chore: update readme text (#235)

Author: rachel-fenichel

README.md

@@ -4,8 +4,46 @@ This plugin for Blockly enables keyboard navigation. It is intended to
 experiment with different actions that might help visually impaired and motor
 impaired people navigate a Blockly workspace.
 
+Keyboard navigation and screenreader support are closely coupled. The Blockly 
+team intends to add screenreader support incrementally in Q2 and Q3 of 2025,
+as we validate the general approach to navigation.
+
+For more planning and timeline information please read the [January 29 timeline post
+on the wiki](https://github.com/google/blockly-keyboard-experimentation/wiki/Jan-29-Timeline).
+
+## End-user instructions
+
 You can explore the current state of the plugin on the [test page](https://google.github.io/blockly-keyboard-experimentation/).
 
+To use keyboard navigation, click on the workspace or press tab until you 
+reach the workspace.
+
+Once browser focus is on the Blockly workspace, you can use arrow keys to 
+move a **cursor** around the workspace. You can use keyboard shortcuts to 
+take actions at the cursor. 
+
+For instance, you can move the cursor to a 
+dropdown field and press the `Enter` key to edit the field.
+
+The available actions depend on the cursor location. For instance, if the 
+cursor is on a block you can copy it with `Ctrl + C`.
+
+You can open the toolbox by pressing `T` or pressing `Tab` until the toolbox is
+highlighted. Just like the workspace, you can use the arrow keys to move around
+the toolbox and select a block. Pressing `Enter` will place the block at the
+cursor's location on the workspace.
+
+If you don't know which actions are available at your cursor location, you 
+can press `Ctrl + Enter` to open the context menu and see a list of actions.
+
+### Giving feedback
+
+If you use the test page and find a bug, please let us know by opening an issue
+on this repository! Include information about how to reproduce the bug, what
+the bad behaviour was, and what you expected it to do. The Blockly team will 
+triage the bug and add it to the roadmap.
+
+### Note on @blockly/keyboard-navigation plugin
 There is also an [existing keyboard navigation plugin](https://www.npmjs.com/package/@blockly/keyboard-navigation). That plugin may be where
 a finalized version of keyboard navigation eventually lives. But for now, this
 is where experimentation will be done.