fix deps, configure eslint, prettier, typescript

.gitignore

@@ -0,0 +1,18 @@
+# See https://help.github.com/articles/ignoring-files/ for more about ignoring files.
+
+# dependencies
+node_modules
+.pnp
+.pnp.js
+
+# testing
+coverage
+
+# misc
+.DS_Store
+*.pem
+
+# debug
+npm-debug.log*
+yarn-debug.log*
+yarn-error.log*