[Improvement] Add markdown linter and fix linting errors (#171)

.github/CONTRIBUTING.md

.github/ISSUE_TEMPLATE/error-report.md

.github/ISSUE_TEMPLATE/feature_request.md

.github/workflows/build.yml

.pre-commit-config.yaml

README.md

configs/ann/README.md

configs/ccnet/README.md

configs/danet/README.md

configs/deeplabv3/README.md

configs/deeplabv3plus/README.md

configs/dnlnet/README.md

configs/emanet/README.md

configs/encnet/README.md

configs/fastscnn/README.md

configs/fcn/README.md

configs/fp16/README.md

configs/gcnet/README.md

configs/hrnet/README.md

configs/mobilenet_v2/README.md