Add initial Microsoft Teams support

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

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

@@ -0,0 +1,21 @@
+// Code generated by msgraph-generate.go DO NOT EDIT.
+
+package msgraph
+
+// ChatMessageAttachment undocumented
+type ChatMessageAttachment struct {
+	// Object is the base model of ChatMessageAttachment
+	Object
+	// ID undocumented
+	ID *string `json:"id,omitempty"`
+	// ContentType undocumented
+	ContentType *string `json:"contentType,omitempty"`
+	// ContentURL undocumented
+	ContentURL *string `json:"contentUrl,omitempty"`
+	// Content undocumented
+	Content *string `json:"content,omitempty"`
+	// Name undocumented
+	Name *string `json:"name,omitempty"`
+	// ThumbnailURL undocumented
+	ThumbnailURL *string `json:"thumbnailUrl,omitempty"`
+}