updt(inst.guide): add alerts for cycle note
feat(modeler-inst): Add installation guide modeler

refer to #cam-1066
feat(enterprise): Add release chapter

related to #cam-1310
Merge branch 'master' of https://github.com/camunda/docs.camunda.org
fix(navigation): rename java to javadoc
fix(references): change order and links on index
feat(userguide): add history docs
Merge branch 'live'
Merge branch 'live' of github.com:camunda/docs.camunda.org into live
Merge branch 'master' into live
Merge branch 'live' into 7.0