[docs] missing docs (v1.1)

[nmetulev]

This issue is tracking features that have not yet been added to the docs and must be added before for next release:

• mgt-get Adding mgt-get #187
• eventClick event on Agenda [Agenda] Adding eventClick event #181
• loading and the error templates in people picker People Picker improvements #163
• inherit-details attribute in person-card [mgt-person-card] added inherit-details attribute  #155
• group-id attribute in people Added group-id poroperty for people #150
• browser support [Doc] Call out which browsers are supported in the Docs #183
• mgt-tasks Adding support for assigning people in tasks and much more #188
• ProxyProvider Added Proxy provider #191
• template support for $index and $parent Templates - introducing $index and $parent #196
• person-card template context update Fix for templates not rendering children in the right order #195
• link to sharepoint sample readme from sharepoint provider docs (57e2f8a)
• update all component documentation to list attributes first (right now some docs show properties first)
• taskFilter Adding taskFilter property to mgt-tasks #211
• login custom properties [mgt-login] fixes signout bug and adds more css custom properties #225