Enable markdownlint rules MD003,MD005,MD007

Lint Markdown

https://github.com/DavidAnson/markdownlint#rules--aliases

.github/linters/.markdown-lint.yml

@@ -4,15 +4,6 @@
 # MD001 heading-increment/header-increment - Heading levels should only increment by one level at a time
 MD001: false
 
-# MD003 heading-style/header-style - Heading style
-MD003: false
-
-# MD005 list-indent - Inconsistent indentation for list items at the same level
-MD005: false
-
-# MD007 ul-indent - Unordered list indentation
-MD007: false
-
 # MD010 no-hard-tabs - Hard tabs
 MD010: false
 

TODO.md

-Thing to Do in the future
-===
+# Thing to Do in the future
 
 # After mruby 3.0
 

doc/guides/mrbgems.md

@@ -200,8 +200,8 @@ Version requirement supports following operators:
 * '>=': is equal or greater
 * '<=': is equal or lesser
 * '~>': is equal or greater and is lesser than the next major version
-    * example 1: '~> 2.2.2' means '>= 2.2.2' and '< 2.3.0'
-    * example 2: '~> 2.2'   means '>= 2.2.0' and '< 3.0.0'
+  * example 1: '~> 2.2.2' means '>= 2.2.2' and '< 2.3.0'
+  * example 2: '~> 2.2'   means '>= 2.2.0' and '< 3.0.0'
 
 When more than one version requirements is passed, the dependency must satisfy all of it.
 
@@ -215,7 +215,7 @@ use `MRuby::Build#gem` in the build configuration to override default gem.
 If you have conflicting GEMs use the following method:
 
 * `spec.add_conflict(gem, *requirements)`
-    * The `requirements` argument is same as in `add_dependency` method.
+  * The `requirements` argument is same as in `add_dependency` method.
 
 like following code:
 

doc/guides/symbol.md

@@ -57,13 +57,13 @@ To save RAM, `mruby` can use compile-time allocation of some symbols. You can
 use following macros to get preallocated symbols by including `mruby/presym.h`
 header.
 
- * `MRB_SYM(xor)`    //=> xor    (Word characters)
- * `MRB_SYM_B(xor)`  //=> xor!   (Method with Bang)
- * `MRB_SYM_Q(xor)`  //=> xor?   (Method with Question mark)
- * `MRB_SYM_E(xor)`  //=> xor=   (Method with Equal)
- * `MRB_CVSYM(xor)`  //=> @@xor  (Class Variable)
- * `MRB_IVSYM(xor)`  //=> @xor   (Instance Variable)
- * `MRB_OPSYM(xor)`  //=> ^      (Operator)
+* `MRB_SYM(xor)`    //=> xor    (Word characters)
+* `MRB_SYM_B(xor)`  //=> xor!   (Method with Bang)
+* `MRB_SYM_Q(xor)`  //=> xor?   (Method with Question mark)
+* `MRB_SYM_E(xor)`  //=> xor=   (Method with Equal)
+* `MRB_CVSYM(xor)`  //=> @@xor  (Class Variable)
+* `MRB_IVSYM(xor)`  //=> @xor   (Instance Variable)
+* `MRB_OPSYM(xor)`  //=> ^      (Operator)
 
 For `MRB_OPSYM()`, specify the names corresponding to operators (see
 `MRuby::Presym::OPERATORS` in `lib/mruby/presym.rb` for the names that

doc/mruby3.md

-User visible changes in `mruby3`
-===
+# User visible changes in `mruby3`
 
 # Build System
 

mrbgems/mruby-io/README.md

-mruby-io
-========
+# mruby-io
 
 `IO` and `File` classes for mruby
 

mrbgems/mruby-method/README.md

-mruby-method
-===
+# mruby-method
 
 An implementation of class **Method** and **UnboundMethod** for mruby
 

mrbgems/mruby-pack/README.md

-mruby-pack (pack / unpack)
-=========
+# mruby-pack (pack / unpack)
 
 mruby-pack provides `Array#pack` and `String#unpack` for mruby.
 
@@ -15,34 +14,34 @@ There is no dependency on other mrbgems.
 
 ## Supported template string
 
- - A : arbitrary binary string (space padded, count is width)
- - a : arbitrary binary string (null padded, count is width)
- - C : 8-bit unsigned (unsigned char)
- - c : 8-bit signed (signed char)
- - D, d: 64-bit float, native format
- - E : 64-bit float, little endian byte order
- - e : 32-bit float, little endian byte order
- - F, f: 32-bit float, native format
- - G : 64-bit float, network (big-endian) byte order
- - g : 32-bit float, network (big-endian) byte order
- - H : hex string (high nibble first)
- - h : hex string (low nibble first)
- - I : unsigned integer, native endian (`unsigned int` in C)
- - i : signed integer, native endian (`int` in C)
- - L : 32-bit unsigned, native endian (`uint32_t`)
- - l : 32-bit signed, native endian (`int32_t`)
- - m : base64 encoded string (see RFC 2045, count is width)
- - N : 32-bit unsigned, network (big-endian) byte order
- - n : 16-bit unsigned, network (big-endian) byte order
- - Q : 64-bit unsigned, native endian (`uint64_t`)
- - q : 64-bit signed, native endian (`int64_t`)
- - S : 16-bit unsigned, native endian (`uint16_t`)
- - s : 16-bit signed, native endian (`int16_t`)
- - U : UTF-8 character
- - V : 32-bit unsigned, VAX (little-endian) byte order
- - v : 16-bit unsigned, VAX (little-endian) byte order
- - x : null byte
- - Z : same as "a", except that null is added with *
+- A : arbitrary binary string (space padded, count is width)
+- a : arbitrary binary string (null padded, count is width)
+- C : 8-bit unsigned (unsigned char)
+- c : 8-bit signed (signed char)
+- D, d: 64-bit float, native format
+- E : 64-bit float, little endian byte order
+- e : 32-bit float, little endian byte order
+- F, f: 32-bit float, native format
+- G : 64-bit float, network (big-endian) byte order
+- g : 32-bit float, network (big-endian) byte order
+- H : hex string (high nibble first)
+- h : hex string (low nibble first)
+- I : unsigned integer, native endian (`unsigned int` in C)
+- i : signed integer, native endian (`int` in C)
+- L : 32-bit unsigned, native endian (`uint32_t`)
+- l : 32-bit signed, native endian (`int32_t`)
+- m : base64 encoded string (see RFC 2045, count is width)
+- N : 32-bit unsigned, network (big-endian) byte order
+- n : 16-bit unsigned, network (big-endian) byte order
+- Q : 64-bit unsigned, native endian (`uint64_t`)
+- q : 64-bit signed, native endian (`int64_t`)
+- S : 16-bit unsigned, native endian (`uint16_t`)
+- s : 16-bit signed, native endian (`int16_t`)
+- U : UTF-8 character
+- V : 32-bit unsigned, VAX (little-endian) byte order
+- v : 16-bit unsigned, VAX (little-endian) byte order
+- x : null byte
+- Z : same as "a", except that null is added with *
 
 ## License
 

mrbgems/mruby-socket/README.md

-mruby-socket
-============
+# mruby-socket
 
 "mruby-socket" mrbgem provides BSD socket interface for mruby.
 API is compatible with CRuby's "socket" library.