fix: fix markdown lint errors

[chenrui333]

seeing

markdownlint-cli2 v0.13.0 (markdownlint v0.34.0)
Finding: runatlantis.io/**/*.md
Linting: 53 file(s)
Summary: 1[8](https://github.com/runatlantis/atlantis/actions/runs/10985180193/job/30496678585?pr=4934#step:3:9) error(s)
Error: runatlantis.io/docs/custom-workflows.md:486:1 MD004/ul-style Unordered list style [Expected: asterisk; Actual: dash] https://github.com/DavidAnson/markdownlint/blob/v0.34.0/doc/md004.md
Error: runatlantis.io/docs/custom-workflows.md:486 MD032/blanks-around-lists Lists should be surrounded by blank lines [Context: "- Appending tags to every reso..."] https://github.com/DavidAnson/markdownlint/blob/v0.34.0/doc/md032.md
Error: runatlantis.io/docs/custom-workflows.md:487:1 MD004/ul-style Unordered list style [Expected: asterisk; Actual: dash] https://github.com/DavidAnson/markdownlint/blob/v0.34.0/doc/md004.md
Error: runatlantis.io/docs/repo-and-project-permissions.md:14:72 MD00[9](https://github.com/runatlantis/atlantis/actions/runs/10985180193/job/30496678585?pr=4934#step:3:10)/no-trailing-spaces Trailing spaces [Expected: 0 or 2; Actual: 1] https://github.com/DavidAnson/markdownlint/blob/v0.34.0/doc/md009.md
Error: runatlantis.io/docs/repo-and-project-permissions.md:23 MD022/blanks-around-headings Headings should be surrounded by blank lines [Expected: 1; Actual: 0; Below] [Context: "### Why check permissions twice?"] https://github.com/DavidAnson/markdownlint/blob/v0.34.0/doc/md022.md
Error: runatlantis.io/docs/repo-and-project-permissions.md:59 MD022/blanks-around-headings Headings should be surrounded by blank lines [Expected: 1; Actual: 0; Below] [Context: "### Restrict production changes"] https://github.com/DavidAnson/markdownlint/blob/v0.34.0/doc/md022.md
Error: runatlantis.io/docs/repo-and-project-permissions.md:61:78 MD009/no-trailing-spaces Trailing spaces [Expected: 0 or 2; Actual: 1] https://github.com/DavidAnson/markdownlint/blob/v0.34.0/doc/md009.md
Error: runatlantis.io/docs/repo-and-project-permissions.md:66 MD031/blanks-around-fences Fenced code blocks should be surrounded by blank lines [Context: "```yaml"] https://github.com/DavidAnson/markdownlint/blob/v0.34.0/doc/md031.md
Error: runatlantis.io/docs/repo-and-project-permissions.md:72 MD031/blanks-around-fences Fenced code blocks should be surrounded by blank lines [Context: "```shell"] https://github.com/DavidAnson/markdownlint/blob/v0.34.0/doc/md031.md
Error: runatlantis.io/docs/repo-and-project-permissions.md:[10](https://github.com/runatlantis/atlantis/actions/runs/10985180193/job/30496678585?pr=4934#step:3:11)1 MD031/blanks-around-fences Fenced code blocks should be surrounded by blank lines [Context: "```"] https://github.com/DavidAnson/markdownlint/blob/v0.34.0/doc/md031.md
Error: runatlantis.io/docs/repo-and-project-permissions.md:102 MD022/blanks-around-headings Headings should be surrounded by blank lines [Expected: 1; Actual: 0; Above] [Context: "## Reference"] https://github.com/DavidAnson/markdownlint/blob/v0.34.0/doc/md022.md
Error: runatlantis.io/docs/repo-and-project-permissions.md:[12](https://github.com/runatlantis/atlantis/actions/runs/10985180193/job/30496678585?pr=4934#step:3:13)0:126 MD009/no-trailing-spaces Trailing spaces [Expected: 0 or 2; Actual: 1] https://github.com/DavidAnson/markdownlint/blob/v0.34.0/doc/md009.md
Error: runatlantis.io/docs/repo-and-project-permissions.md:122 MD012/no-multiple-blanks Multiple consecutive blank lines [Expected: 1; Actual: 2] https://github.com/DavidAnson/markdownlint/blob/v0.34.0/doc/md012.md
Error: runatlantis.io/docs/repo-and-project-permissions.md:132 MD012/no-multiple-blanks Multiple consecutive blank lines [Expected: 1; Actual: 2] https://github.com/DavidAnson/markdownlint/blob/v0.34.0/doc/md012.md
Error: runatlantis.io/docs/repo-and-project-permissions.md:152:76 MD009/no-trailing-spaces Trailing spaces [Expected: 0 or 2; Actual: 1] https://github.com/DavidAnson/markdownlint/blob/v0.34.0/doc/md009.md
Error: runatlantis.io/docs/repo-and-project-permissions.md:156 MD040/fenced-code-language Fenced code blocks should have a language specified [Context: "```"] https://github.com/DavidAnson/markdownlint/blob/v0.34.0/doc/md040.md
Error: runatlantis.io/docs/repo-and-project-permissions.md:165 MD032/blanks-around-lists Lists should be surrounded by blank lines [Context: "* A non-zero exit code means t..."] https://github.com/DavidAnson/markdownlint/blob/v0.34.0/doc/md032.md
Error: runatlantis.io/docs/repo-and-project-permissions.md:169:1 MD007/ul-indent Unordered list indentation [Expected: 2; Actual: 3] https://github.com/DavidAnson/markdownlint/blob/v0.34.0/doc/md007.md
Error: Failed with exit code: 1

in https://github.com/runatlantis/atlantis/actions/runs/10985180193/job/30496678585?pr=4934

relates to #4934