docs: Extend go install tutorial.

---------

Co-authored-by: norwnd <norwnd>

README.md

@@ -28,16 +28,17 @@ changes may be written to a config file in a platform-specific location:
 
 ## Build and installation
 
-- **Install Go 1.19 or 1.20**
+- **Install Go 1.19 or higher version**
 
  Installation instructions can be found here: https://golang.org/doc/install.
  Ensure Go was installed properly and is a supported version:
  ```sh
  $ go version
  $ go env GOROOT GOPATH
  ```
- NOTE: `GOROOT` and `GOPATH` must not be on the same path. It is recommended
- to add `$GOPATH/bin` to your `PATH` according to the Golang.org instructions.
+ NOTE: if `GOROOT` and `GOPATH` are initialized they must not be on the same path.
+ It is recommended to add `$GOPATH/bin` to your `PATH` according to the Golang.org
+ instructions.
 
 - **Build or Update dcrctl**
 
@@ -59,6 +60,14 @@ changes may be written to a config file in a platform-specific location:
  Alternatively, a development build can be performed by running `go install` in
  a locally checked-out repository.
 
+ If you want to easily access `dcrctl` from the command-line without having to
+ type the full path to the binary every time, ensure the bin directory rooted
+ at the path reported by `go env GOPATH` is added to your system path:
+
+ * macOS: [how to add binary to your PATH](https://gist.github.com/nex3/c395b2f8fd4b02068be37c961301caa7#mac-os-x)
+ * Windows: [how to add binary to your PATH](https://gist.github.com/nex3/c395b2f8fd4b02068be37c961301caa7#windows)
+ * Linux and other Unix: [how to add binary to your PATH](https://gist.github.com/nex3/c395b2f8fd4b02068be37c961301caa7#linux)
+
 ## Developing
 
 When developing either the `dcrd` or `dcrwallet` RPC servers and making