* New command `show`. Adds support for retrieving the release notes from Github. Shown automatically after update.
* Improve code
* Don't show release notes by default, but show how to view them
* Add version flag for release notes
* Escape path
The io/ioutil package has been deprecated as of Go 1.16, see
https://golang.org/doc/go1.16#ioutil. This commit replaces the existing
io/ioutil functions with their new definitions in io and os packages.
Signed-off-by: Eng Zer Jun <engzerjun@gmail.com>