[Backport] Version bumps from 1.6.0 release (#2965)

This PR backports version bumps from release branch
`release-polkadot-v1.6.0` back to `master` and also moved `prdoc` files
related to the release to the appropriate folder

polkadot/Cargo.toml

@@ -18,7 +18,7 @@ rust-version = "1.64.0"
 readme = "README.md"
 authors.workspace = true
 edition.workspace = true
-version = "1.5.0"
+version = "1.6.0"
 default-run = "polkadot"
 
 [lints]

polkadot/node/primitives/src/lib.rs

@@ -58,7 +58,7 @@ pub use disputes::{
 /// relatively rare.
 ///
 /// The associated worker binaries should use the same version as the node that spawns them.
-pub const NODE_VERSION: &'static str = "1.5.0";
+pub const NODE_VERSION: &'static str = "1.6.0";
 
 // For a 16-ary Merkle Prefix Trie, we can expect at most 16 32-byte hashes per node
 // plus some overhead:

polkadot/runtime/westend/src/lib.rs

@@ -147,7 +147,7 @@ pub const VERSION: RuntimeVersion = RuntimeVersion {
 	spec_name: create_runtime_str!("westend"),
 	impl_name: create_runtime_str!("parity-westend"),
 	authoring_version: 2,
-	spec_version: 1_005_000,
+	spec_version: 1_006_000,
 	impl_version: 0,
 	apis: RUNTIME_API_VERSIONS,
 	transaction_version: 24,