rename toplevel header from Contribute to Development (#10472)

Author: scottyhq

doc/contribute/index.rst

@@ -1,11 +1,12 @@
-##################
-Contributors Guide
-##################
+########################
+Xarray Developer's Guide
+########################
 
 We welcome your skills and enthusiasm at the Xarray project! There are numerous opportunities to
 contribute beyond just writing code.
 All contributions, including bug reports, bug fixes, documentation improvements, enhancement suggestions,
-and other ideas are welcome.
+and other ideas are welcome. Please review our Contributor's guide for more guidance.
+In this section you will also find documentation on the internal organization of Xarray's source code, the roadmap for current development priorities, as well as how to engage with core maintainers of the Xarray codebase.
 
 .. toctree::
    :maxdepth: 2

doc/index.rst

@@ -70,5 +70,5 @@ efficient, and fun!
    Gallery <gallery>
    API Reference <api>
    Get Help <get-help/help-diagram>
-   Contribute <contribute/index>
+   Development <contribute/index>
    Release Notes <whats-new>