Add changelog notes for v1.3.0 release

[elsevers]

No description provided.

[noguchi-takahiro]

Thank you @elsevers. This looks good.

Level 1 review summary:

• Does the code run without error and produce the expected result? N/A
• Does the code comply with the code guidelines? N/A
• Does the code documentation comply with the documentation guidelines? N/A
• Is the writing, grammar, and syntax correct and clear? Yes
• Is the changeset compliant with the eMach architecture? Yes
• Does this review consider whether this physics are accurate? N/A
• Are the correct issues being closed (and are there no partially completed issues)? N/A
• Did the reviewer change the release schedule for the issues bing closed? No
• Did the reviewer change the branch the PR is being merged into? No
• Is PR approved to Level 2? Yes