Add support for linting Markdown code blocks

[evanrittenhouse]

Adds support for Markdown code blocks.

I'm trying to keep all traits as generic as possible so that we can re-use them for embedded languages or other lintable languages down the road.

Closes #3792 when done, though I expect that this will have a lot of iteration on design and such before it's done.

[github-actions]

PR Check Results

Ecosystem

✅ ecosystem check detected no changes.

Benchmark

Linux

group                                      main                                   pr
-----                                      ----                                   --
linter/all-rules/large/dataset.py          1.00     14.0±0.02ms     2.9 MB/sec    1.00     13.9±0.05ms     2.9 MB/sec
linter/all-rules/numpy/ctypeslib.py        1.01      3.4±0.00ms     4.9 MB/sec    1.00      3.4±0.00ms     4.9 MB/sec
linter/all-rules/numpy/globals.py          1.02    424.9±0.57µs     6.9 MB/sec    1.00    416.3±0.51µs     7.1 MB/sec
linter/all-rules/pydantic/types.py         1.01      5.8±0.01ms     4.4 MB/sec    1.00      5.8±0.01ms     4.4 MB/sec
linter/default-rules/large/dataset.py      1.01      6.8±0.01ms     6.0 MB/sec    1.00      6.7±0.01ms     6.1 MB/sec
linter/default-rules/numpy/ctypeslib.py    1.01   1461.7±5.55µs    11.4 MB/sec    1.00   1444.7±4.37µs    11.5 MB/sec
linter/default-rules/numpy/globals.py      1.02    163.7±0.83µs    18.0 MB/sec    1.00    160.3±2.37µs    18.4 MB/sec
linter/default-rules/pydantic/types.py     1.00      3.0±0.00ms     8.4 MB/sec    1.00      3.0±0.01ms     8.4 MB/sec
parser/large/dataset.py                    1.01      5.5±0.00ms     7.4 MB/sec    1.00      5.4±0.03ms     7.5 MB/sec
parser/numpy/ctypeslib.py                  1.03   1078.7±2.32µs    15.4 MB/sec    1.00   1051.5±3.56µs    15.8 MB/sec
parser/numpy/globals.py                    1.03    110.3±0.24µs    26.7 MB/sec    1.00    106.9±0.20µs    27.6 MB/sec
parser/pydantic/types.py                   1.01      2.3±0.00ms    10.9 MB/sec    1.00      2.3±0.00ms    11.1 MB/sec

Windows

group                                      main                                   pr
-----                                      ----                                   --
linter/all-rules/large/dataset.py          1.02     16.9±0.18ms     2.4 MB/sec    1.00     16.5±0.22ms     2.5 MB/sec
linter/all-rules/numpy/ctypeslib.py        1.01      4.3±0.03ms     3.9 MB/sec    1.00      4.3±0.02ms     3.9 MB/sec
linter/all-rules/numpy/globals.py          1.02    441.3±4.88µs     6.7 MB/sec    1.00    431.0±4.25µs     6.8 MB/sec
linter/all-rules/pydantic/types.py         1.01      7.1±0.03ms     3.6 MB/sec    1.00      7.1±0.03ms     3.6 MB/sec
linter/default-rules/large/dataset.py      1.02      8.5±0.03ms     4.8 MB/sec    1.00      8.4±0.04ms     4.9 MB/sec
linter/default-rules/numpy/ctypeslib.py    1.01   1760.7±7.95µs     9.5 MB/sec    1.00   1743.6±7.48µs     9.5 MB/sec
linter/default-rules/numpy/globals.py      1.01    189.2±1.38µs    15.6 MB/sec    1.00    188.0±5.16µs    15.7 MB/sec
linter/default-rules/pydantic/types.py     1.01      3.8±0.01ms     6.7 MB/sec    1.00      3.8±0.07ms     6.7 MB/sec
parser/large/dataset.py                    1.05      7.0±0.02ms     5.8 MB/sec    1.00      6.7±0.02ms     6.1 MB/sec
parser/numpy/ctypeslib.py                  1.05   1324.9±8.05µs    12.6 MB/sec    1.00   1267.3±7.60µs    13.1 MB/sec
parser/numpy/globals.py                    1.04    136.8±0.72µs    21.6 MB/sec    1.00    131.6±1.87µs    22.4 MB/sec
parser/pydantic/types.py                   1.04      2.9±0.02ms     8.7 MB/sec    1.00      2.8±0.01ms     9.0 MB/sec

[evanrittenhouse]

A local test file shows it's currently at least working and picking up Python code blocks as expected. Next issue is figuring out why the BoundedCodeBlock's offset isn't applying in the diagnostic -> message conversion.