Motivation

Typo in docs/en/user_guides/visualization_feature_map.md.

Modification

reature -> feature

Checklist

- [x] Pre-commit or other linting tools are used to fix the potential
lint issues.
- [x] The modification is covered by complete unit tests. If not, please
add more unit test to ensure the correctness.
- [x] If the modification has potential influence on downstream
projects, this PR should be tested with downstream projects, like MMDet
or MMDet3D.
- [x] The documentation has been modified accordingly, like docstring or
example tutorials.