chore(migration): Extend migration guide

related to CAM-933
feat(assignee): Add docs for set assignee

related to CAM-1132
Merge branch 'master' of github.com:camunda/docs.camunda.org
feat(start-event): add docs for asynchronous start event

related to CAM-424
feat(docs): add LDAP, Identity, Auth, Depl. Descr.

add docs on
- LDAP (User guide + installation guide)
- Identity Service
- Authorization Service
- Deployment Descriptor Reference

related to #CAM-819, #CAM-833, #CAM-978
Merge branch 'master' of github.com:camunda/docs.camunda.org

Conflicts:
	site/src/documents/guides/user-guide/chapters/01-bpm-platform.md.eco
chore(docs): typos & bad link
chore(ldap): add ldap spring config example
impr(spring): doc usage of bean name

related to CAM-1093
doc(processes.xml): empty processes.xml

related to #CAM-1136
fix(typo): Fix some typos
feat(rest): add authentication filter docs

related to CAM-822
impr(docs): add list on built-in auth resources
Merge branch 'master' of github.com:camunda/docs.camunda.org
feat(rest): add docs for resteasy specific filter parameter

related to CAM-822
chore(confirm/password): Add confirm. password

related to CAM-1135
Merge branch 'master' of github.com:camunda/docs.camunda.org
fix(user-guide): Update tasklist screen-shots
fix(typo): Fix some typos
Merge branch 'master' of github.com:camunda/docs.camunda.org