Add initial Microsoft Teams support

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

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

@@ -0,0 +1,15 @@
+// Code generated by msgraph-generate.go DO NOT EDIT.
+
+package msgraph
+
+// Agreement undocumented
+type Agreement struct {
+	// Entity is the base model of Agreement
+	Entity
+	// DisplayName undocumented
+	DisplayName *string `json:"displayName,omitempty"`
+	// IsViewingBeforeAcceptanceRequired undocumented
+	IsViewingBeforeAcceptanceRequired *bool `json:"isViewingBeforeAcceptanceRequired,omitempty"`
+	// Files undocumented
+	Files []AgreementFile `json:"files,omitempty"`
+}