docs(scalable): update docs for symbolic icons

src/scalable/README.md

@@ -5,10 +5,11 @@
  - To edit the icons you will need `inkscape` and you'll need `ruby` installed to run the render script.
 
 **[source-symbolic.svg](./source-symbolic.svg) - the source files that contains all of the symbolic icons**
- - each layer in this source file corresponds to a icon `context` and the icons are sorted accordingly
- - each icon should be drawn within an 16x16 pixel square and use only 1 colour
- - when complete, group all elements within a 16x16 rectangle (with no fill or stroke) and label that group with the `icon-name`
+ - Each layer in this source file corresponds to a icon `context` and the icons are sorted accordingly
+ - Each icon should be drawn within an 16x16 pixel square and use only 1 colour
+ - When complete, group all elements within a 16x16 rectangle (with no stroke and #888888 fill at 1% opacity for later modification) and label that group with the `icon-name` (less the `-symbolic` suffix).
 
 **[extract-symbolic-icons.rb](./extract-symbolic-icons.rb) - the render script**
- - extract any new symbolic icons from the source SVG by passing the icon name to this script: `./extract-symbolic-icons.rb <icon-name>`
- - or, if run generally, this script will look through the entire source file to render any new icons (if a new icon does not have a correct label the script will fail)
+ - The recommended way to render modified icons is to delete the output file and re-render using the [`master-render.py`](../../master-render.py) script. Alternatively:
+ - Extract any new symbolic icons from the source SVG by passing the icon name to this script: `./extract-symbolic-icons.rb <icon-name>`
+ - Or, if run generally, this script will look through the entire source file to render any new icons (if a new icon does not have a correct label the script will fail)