Update READMEs, fix links (#7176)

* Re-generate READMEs to fix doc links; set readme field in package manifests

* Re-generate READMEs to fix doc links; set readme field in package manifests

* Re-generate READMEs to fix doc links; set readme field in package manifests

* Re-generate READMEs to fix doc links; set readme field in package manifests

* Revert stuff that shouldn't have been committed

* Revert stuff that shouldn't have been committed

* Fix parent relative link generation

* Manually remove this incorrect link for now.

substrate/primitives/tracing/Cargo.toml

@@ -7,6 +7,7 @@ edition = "2018"
 homepage = "https://substrate.dev"
 repository = "https://github.com/paritytech/substrate/"
 description = "Instrumentation primitives and macros for Substrate."
+readme = "README.md"
 
 [package.metadata.docs.rs]
 # let's default to wasm32

substrate/primitives/tracing/README.md

@@ -1,6 +1,6 @@
 Substrate tracing primitives and macros.
 
-To trace functions or invidual code in Substrate, this crate provides [`tracing_span`]
+To trace functions or invidual code in Substrate, this crate provides [`within_span`]
 and [`enter_span`]. See the individual docs for how to use these macros.
 
 Note that to allow traces from wasm execution environment there are