Make mdbook-lint useful

[BartMassey]

We now have CI for mdbook-lint in the mdbook-lint branch here. But it's mostly noise and analysis errors. We need to see if we can do something useful with it, or if it's just a dead-end.

[joshrotenberg]

mdbook-lint author here, let me know if I can help out in any way. Happy to fix any issues you find.

[joshrotenberg]

Actually, I found a few bugs in mdbook-lint:

1. MD010 was flagging tabs inside code blocks even when code_blocks = false was set - the config option was documented but not actually implemented. Fixed in #347.

2. MD052 wasn't recognizing reference link definitions inside blockquotes. Fixed in #348.

I will cut a new release to include these shortly.

For the remaining issues, running mdbook-lint fix will auto-fix about half of them (list indentation, trailing spaces, emphasis style, etc).

Here's an updated config based on what you already have that keeps the useful checks as errors and turns the style stuff into warnings or disables it:

# mdbook-lint configuration for discovery-mb2
# This configuration focuses on catching important issues while being practical

# Disable rules that are less relevant for this educational book
disabled-rules = [
  "MD013",  # Line length - educational content often has long lines
  "MD033",  # HTML allowed - mdBook supports it
  "MD036",  # Emphasis as heading - common in educational content
  "MD014",  # Dollar signs in commands - common in tutorials
  "CONTENT004",  # Sensitive words - not relevant here
  "CONTENT005",  # Link accessibility - not critical for technical book
  "CONTENT011",  # Sentence case headings - style preference
]

# Configure specific rules
[MD007]
indent = 4  # Allow 4-space indentation for nested lists

[MD009]
br_spaces = 2  # Allow 2 trailing spaces for line breaks

[MD010]
code_blocks = false  # Ignore hard tabs inside code blocks

[MD041]
level = 2  # Don't require h1 to be first line in every chapter

# Content rules configuration
[CONTENT001]
enabled = false  # Don't flag TODOs (they might be legitimate placeholders)

[CONTENT003]
enabled = false  # Don't flag placeholder text like "XXX"

Note: Changed code_blocks = true to code_blocks = false - the config was inverted (false = ignore tabs in code blocks).

Happy to open a PR with the auto-fixes if that would help.

[BartMassey]

@joshrotenberg Thanks much for this! I'm working on bringing the mainline book up to a good working version, and I'll take the liberty of bugging you after that and we'll work out a plan for what needs to be cleaned up and what needs to be left alone.