Change docs landing page to link to transformExtent
Document map DOM elements
Merge pull request #2355 from probins/mapelements

Document map DOM elements
Merge pull request #2358 from probins/patch-1

Change docs landing page to link to transformExtent
Tag always exported methods as api/observable
Fix missing backtick in ol.Object docs
Merge pull request #2365 from probins/patch-1

Fix missing backtick in ol.Object docs
Merge pull request #2364 from probins/observable

Tag always exported methods as api/observable