Add new defcustom js-jsx-indent-level

* lisp/progmodes/js.el (js-jsx-indent-level): New variable for users
to set JSX indentation differently than JS, like before.
(js-jsx--contextual-indentation): Respect js-jsx-indent-level when
it’s set.

* test/manual/indent/jsx-indent-level.jsx: New test for
js-jsx-indent-level.

1 files changed, 13 insertions, 0 deletions

diff --git a/test/manual/indent/jsx-indent-level.jsx b/test/manual/indent/jsx-indent-level.jsx
new file mode 100644
index 00000000000..0a84b9eb77a
--- /dev/null
+++ b/test/manual/indent/jsx-indent-level.jsx
@@ -0,0 +1,13 @@
+return (
+    <element>
+      <element>
+        Hello World!
+      </element>
+    </element>
+)
+
+// Local Variables:
+// indent-tabs-mode: nil
+// js-indent-level: 4
+// js-jsx-indent-level: 2
+// End: