cat_pool specs markdown issues

[rootulp]

Context

#2207 just merged. It passes markdownlint on CI but fails for me locally. I have markdownlint 0.35.0 installed locally.

Problem

$ make lint
--> Running golangci-lint
--> Running markdownlint
specs/src/specs/cat_pool.md:6 MD001/heading-increment/header-increment Heading levels should only increment by one level at a time [Expected: h2; Actual: h3]
specs/src/specs/cat_pool.md:90:1 MD007/ul-indent Unordered list indentation [Expected: 2; Actual: 4]
specs/src/specs/cat_pool.md:91:1 MD007/ul-indent Unordered list indentation [Expected: 2; Actual: 4]
specs/src/specs/cat_pool.md:102 MD012/no-multiple-blanks Multiple consecutive blank lines [Expected: 1; Actual: 2]
make: *** [lint] Error 1

Proposal

1. Fix the markdowlint errors above
2. Markdown lint CI not failing on non-respected rules #2212