These tests are broken for mac because `/var/folder` is a sym link to
`/private/var/folder`.

Signed-off-by: Terry Howe <tlhowe@amazon.com>

fix: #437 
Description: Updated link of oras-go in readme.md file

Signed-off-by: khanjasir90 <khanmohdjasir@gmail.com>

Update Go support window to [1.19, 1.20]

Fixes: #425
Signed-off-by: Asmit2952 <asmitbm2952002@gmail.com>

Add
[CODEOWNERS](https://docs.github.com/en/repositories/managing-your-repositorys-settings-and-features/customizing-your-repository/about-code-owners)
based on the
[OWNERS.md](https://github.com/oras-project/oras-go/blob/main/OWNERS.md)
file.

Signed-off-by: Shiwei Zhang <shizh@microsoft.com>

Having multiple entries with the same path results in that only the last
entry takes effect.
This PR combines multiple entries with the same path into a single
entry.

Signed-off-by: Shiwei Zhang <shizh@microsoft.com>

Fixes: #449
Signed-off-by: Lixia (Sylvia) Lei <lixlei@microsoft.com>