update Replacer

[light-and-ray]

Info

https://github.com/light-and-ray/sd-webui-replacer Update description

Checklist:

• [x] I have read the Readme.md
• [x] The description is written in English.
• [x] The index.json and extension_template.json have not been modified.
• [x] The entry is placed in the extensions directory with the .json file extension.