Changes Emscripten SDK version to match that used to compile the default export
templates used by Godot 3.5 (in this case 3.1.14 as can be seen here:
https://github.com/godotengine/build-containers/blob/3.5/Dockerfile.javascript).
This means we no longer need to compile custom export templates when
exporting HTML5 for Godot 3.5. Exports from other Godot versions may
requiring compiling the GDNative library with a different version of the
Emscripten SDK.
- Changes renderer from GLES3 -> GLES2 and reduces MSAA level to better
support HTML5 export.
- Updates GitHub Action to export HTML5 and upload as a build artifact.
- Adds Cypress test to smoke test HTML5 export.
Updates theme names to be compatible with Godot 3.5 (no spaces),
consistent with other Godot theme item names (snake_case), and
match the color names listed on the
[ANSI escape code wikipedia page](https://en.wikipedia.org/wiki/ANSI_escape_code#3-bit_and_4-bit).
Deprecates the old names and warns users to change them.
As cols and rows are read only (i.e. automatically determined by rect
and font size) there is no need for the properties to be exposed.
Instead, users can get the calculated cols and rows using the get_cols()
and get_rows() methods.
Makes it easier to keep documentation up to date and can deploy with
GitHub pages.
README.md moved to docs/README.md and is shared with GitHub Pages home
page.
