Move Subxt crate into a subfolder (#424)

* move into subfolder step 1

* Make folders a workspace again

* Move examples into their own workspace crate to make them more visible and easier to run

* clippy fix

* newline

* tweak releasing steps for folder move

* reference exampels more clearly in top level readme

RELEASING.md

@@ -55,7 +55,7 @@ We also assume that ongoing work done is being merged directly to the `master` b
         sleep 10 && \
         (cd macro && cargo hack publish --no-dev-deps --allow-dirty) && \
         sleep 10 && \
-        cargo publish && \
+        (cd subxt && cargo publish) && \
         sleep 10 && \
         (cd cli && cargo publish);
     ```