This PR addresses that by:
* rendering oneway arrows on more than `subclass=cycleway`
* less opacity for path/footway casing
* adding the thin black casing to bridges
* adding `subclass=steps` & `subclass=bridleway` rendering
* render `bicycle=designated` as `subclass=cycleway` and `horse=designated` as `subclass=bridleway` (bike taking priority)
* improved tunnel rendering with double casing & adding main line
* made casing min zoom consistent across subclasses
All of these changes were made to mimic OSM Carto.
* OpenMapTiles style
* Rename style snippets from layer_name.json to defaultstyle.json
* Add README to icons dir.
* Add README to icons dir.
* Rename snippets to style.json
* Fix spritezero - move icons to svg subdir
* Move icons from style/icons/svg directly to style/icons
Co-authored-by: Tomas Pohanka <TomPohys@gmail.com>