Add @api stable annotations to ol.tilegrid.TileGrid
Add @api stable annotations to olx.tilegrid.TileGridOptions
Add @api stable annotations to ol.tilegrid.WMTS
Add @api stable annotations to olx.tilegrid.WMTSOptions
Mark all WMTS functions/options as experimental
Merge pull request #2614 from elemoine/tilegrid-stability

Add @api stable annotations tilegrid functions and options