Hailiu/bot service web app settings (Azure#12995)

* add webAppBotSettings get operation

* Revert "add webAppBotSettings get operation"

This reverts commit 6fa8467.

* add api-version 2021-03-01 with webAppBotSettings

* rename sub type from webAppBotSettings to hostSettings

* add more descriptive descriptions to HostSettings

* update api-version to 2021-03-01 for examples

* add new bot kind

* Update specification/botservice/resource-manager/Microsoft.BotService/stable/2021-03-01/botservice.json

Co-authored-by: Mark Cowlishaw <markcowl@microsoft.com>

* Update specification/botservice/resource-manager/Microsoft.BotService/stable/2021-03-01/botservice.json

Co-authored-by: Mark Cowlishaw <markcowl@microsoft.com>

* rename check name availability definition names

* add azurebot as custom words

* fix custom-words.txt file name

* put custom words in the right place

* rename HostSettings defintion to HostSettingsResponse

* revert definition names so SDK back compat is not broken

Co-authored-by: Mark Cowlishaw <markcowl@microsoft.com>

custom-words.txt

@@ -185,6 +185,7 @@ AzureAD
 azureADMetrics
 azureasyncoperations
 azureblob
+azurebot
 azurecli
 azurecr
 azuredatabasemigrationservice