Adjusting the position of the worksapce root definition

Author: heisen-li

src/doc/src/reference/workspaces.md

@@ -15,9 +15,6 @@ The key points of workspaces are:
   sections in `Cargo.toml` are only recognized in the *root* manifest, and
   ignored in member crates' manifests.
 
-The *workspace root* is the directory where the workspace's `Cargo.toml` 
-is located.
-
 In the `Cargo.toml`, the `[workspace]` table supports the following sections:
 
 * [`[workspace]`](#the-workspace-section) --- Defines a workspace.
@@ -36,11 +33,14 @@ In the `Cargo.toml`, the `[workspace]` table supports the following sections:
 ## The `[workspace]` section
 
 To create a workspace, you add the `[workspace]` table to a `Cargo.toml`:
+
 ```toml
 [workspace]
 # ...
 ```
 
+The directory where the workspace's Cargo.toml is located then becomes so-called the workspace root.
+
 At minimum, a workspace has to have a member, either with a root package or as
 a virtual manifest.