Duplicated items in unordered_map/README.md

[Cc618]

Hello !

Describe the bug
I noticed that the TODO list in unordered_map/README.md contains duplicated items such as count and find.
One entry is checked while the other is unchecked and might be removed.

To Reproduce
Go to unordered_map/README.md, you will see this :

✔️ count
✔️ find
...
❌ count
❌ find

Expected behavior
Unchecked duplicates should be removed like this :

✔️ count
✔️ find
...

[Cc618]

Can I fix this issue ?

[Tuntai]

hi....I have tried working on it. Please do check!

[Cc618]

Ok that's fine, thank you !