Add new rule to Mulan PubL v1 License

[Tang-Kin-Long]

Hi, I am the contributor from RecLicense project of osslab-pku, taking on the issue "Contribute updates back to ScanCode?".
I observe that in Mulan License family, the rule for detecting Mulan Public License, Version 1 (Mulan PubL v1) is not existed.
I've done some tests in local environment to show that existing rules for Mulan PSL v1, ,Mulan PSL v2, Mulan PubL v2 can adequately detect and distinguish Mulan license.
Therefore, currently I only consider to add a new rule mulanpubl-1.0_1.RULE for Mulan PubL v1, which takes the content of mulanpubl-2.0_1.RULE as reference.

Tasks

• Reviewed contribution guidelines
• PR is descriptively titled 📑 and links the original issue above 🔗
• Tests pass -- look for a green checkbox ✔️ a few minutes after opening your PR
  Run tests locally to check for errors.
• Commits are in uniquely-named feature branch and has no merge conflicts 📁
• Updated documentation pages (if applicable)
• Updated CHANGELOG.rst (if applicable)

Signed-off-by: Jianlang Deng csgarytang@gmail.com