Updates README to note that Pootle is not actively maintained

[linghengqian]

• Fixes #6920 .
• Updates README to note that Pootle is not actively maintained. See https://github.com/translate/pootle/issues/6920#issuecomment-1525567199 and https://github.com/translate/pootle/issues/6920#issuecomment-1525596832 .

[linghengqian]

and then add the points you have as the body of the paragraph

• How about this? I updated the commit.
•