Add initial Microsoft Teams support

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

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

@@ -0,0 +1,15 @@
+// Code generated by msgraph-generate.go DO NOT EDIT.
+
+package msgraph
+
+// MarkContent undocumented
+type MarkContent struct {
+	// LabelActionBase is the base model of MarkContent
+	LabelActionBase
+	// FontSize undocumented
+	FontSize *int `json:"fontSize,omitempty"`
+	// Text undocumented
+	Text *string `json:"text,omitempty"`
+	// FontColor undocumented
+	FontColor *string `json:"fontColor,omitempty"`
+}