Add initial Microsoft Teams support

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

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

@@ -0,0 +1,21 @@
+// Code generated by msgraph-generate.go DO NOT EDIT.
+
+package msgraph
+
+// ExternalConnection undocumented
+type ExternalConnection struct {
+	// Entity is the base model of ExternalConnection
+	Entity
+	// Name undocumented
+	Name *string `json:"name,omitempty"`
+	// Description undocumented
+	Description *string `json:"description,omitempty"`
+	// Configuration undocumented
+	Configuration *Configuration `json:"configuration,omitempty"`
+	// Schema undocumented
+	Schema *Schema `json:"schema,omitempty"`
+	// Items undocumented
+	Items []ExternalItem `json:"items,omitempty"`
+	// Operations undocumented
+	Operations []ConnectionOperation `json:"operations,omitempty"`
+}