Add initial Microsoft Teams support

Documentation on https://github.com/42wim/matterbridge/wiki/MS-Teams-setup

vendor/github.com/yaegashi/msgraph.go/beta/ChatModel.go

@@ -0,0 +1,23 @@
+// Code generated by msgraph-generate.go DO NOT EDIT.
+
+package msgraph
+
+import "time"
+
+// Chat undocumented
+type Chat struct {
+	// Entity is the base model of Chat
+	Entity
+	// Topic undocumented
+	Topic *string `json:"topic,omitempty"`
+	// CreatedDateTime undocumented
+	CreatedDateTime *time.Time `json:"createdDateTime,omitempty"`
+	// LastUpdatedDateTime undocumented
+	LastUpdatedDateTime *time.Time `json:"lastUpdatedDateTime,omitempty"`
+	// Members undocumented
+	Members []ConversationMember `json:"members,omitempty"`
+	// Messages undocumented
+	Messages []ChatMessage `json:"messages,omitempty"`
+	// InstalledApps undocumented
+	InstalledApps []TeamsAppInstallation `json:"installedApps,omitempty"`
+}