add ci for eslint

run-eslint.sh

@@ -0,0 +1,18 @@
+#!/bin/sh
+
+set -e
+
+# used this pull request for reference
+# https://github.com/nextcloud/spreed/pull/48
+ESLINT=$(which eslint || true)
+if [ -z "$ESLINT" ]
+then
+    echo "could not find eslint in $PATH"
+    exit 1
+fi
+
+echo checking scripts with $ESLINT
+find -name "*.js" -print0 | xargs -0 $ESLINT
+
+# use this line to test changes locally
+#find src -name "*.js" -exec sh -c 'npx eslint $1' -- {} \;