Rename PAINT to PALETTE (#4161)

* /paint to /palette

* rename paint to palette

* rename the modules in palette to be pallets

* update Structure.adoc

* bump impl

* fix CI directory

* Update docs/Structure.adoc

Co-Authored-By: Benjamin Kampmann <ben@gnunicorn.org>

substrate/bin/node-template/runtime/src/template.rs

@@ -6,7 +6,7 @@
 
 
 /// For more guidance on Substrate modules, see the example module
-/// https://github.com/paritytech/substrate/blob/master/paint/example/src/lib.rs
+/// https://github.com/paritytech/substrate/blob/master/palette/example/src/lib.rs
 
 use support::{decl_module, decl_storage, decl_event, dispatch::Result};
 use system::ensure_signed;