sqlfluff regex update

[benjaminwestern]

Fix: SQLFluff Parsing for js {} Blocks

• Issue: SQLFluff failed with a "templating/parsing error" when formatting .sqlx files containing js {} blocks.
• Cause: The .sqlfluff configuration's regular expression (param_regex) did not recognize js as a valid block type.
• Solution: The param_regex was updated to include js, and js = was added to the configuration.
• Impact: Users can now correctly format files that contain JavaScript blocks. Testing confirms the fix with no regressions.

Not 100% certain this will fix #148 but maybe?

[benjaminwestern]

@ashish10alex just spitballing on this one. Let me know what comes to mind when you see this :)