Change "Browse Charities in Chicago" to "Browse CATEGORY Charities in Chicago" when category selected

[jtrshelley]

On the page where you can jump different categories for a city, have the "Browse charities in Chicago" string reflect which category is highlighted. IE:

Browse arts charities in Chicago OR Browse environment charities in Chicago OR Browse health & wellness charities in Chicago etc.

But if you just select a city and no category, then it should still display "Browse Charities in Chicago"