migrate to typescript

.editorconfig

@@ -0,0 +1,17 @@
+# EditorConfig is awesome: https://EditorConfig.org
+
+# top-most EditorConfig file
+root = true
+
+# Unix-style newlines with a newline ending every file
+[*]
+end_of_line = lf
+insert_final_newline = true
+
+[*.{js,json,ts,tsx}]
+charset = utf-8
+indent_style = space
+indent_size = 4
+
+[package.json]
+indent_size = 2