(https://github.com/ruby/strscan/pull/180)

Since `[](n)` is being interpreted as a Markdown link, it cannot be
displayed as a method call.
I have corrected this by escaping the brackets so that they are
interpreted as strings rather than links.

### Before

ri

```
    #{}[n]     |   <tt>n</tt>th captured substring.    |       +nil+.
```

html

<img width="424" height="217" alt="image"
src="https://github.com/user-attachments/assets/b45601ab-ed1c-4b82-b112-325f12bde197"
/>

### After

ri

```
    #[](n)     |   <tt>n</tt>th captured substring.    |       +nil+.
```

html

<img width="489" height="217" alt="image"
src="https://github.com/user-attachments/assets/1212c147-42a5-4f62-8667-a279ccff67a3"
/>

https://github.com/ruby/strscan/commit/b3d56867fd

(https://github.com/ruby/strscan/pull/179)

### Helper methods link is broken at master branch

To reproduce
1. go to [StringScanner
docs](https://docs.ruby-lang.org/en/master/StringScanner.html)
2. Click to link at line
   > See examples at **helper_methods**
3. Resolved url gives 404:
https://docs.ruby-lang.org/en/master/strscan/helper_methods_md.html

### Fix

Currently link resolves as `href="doc/strscan/helper_methods_md.html"`
Correct link should be resolved as `href="helper_methods_md.html"`

https://github.com/ruby/strscan/commit/adb8678aa6

https://github.com/ruby/strscan/commit/29ad49f89d

(https://github.com/ruby/strscan/pull/162)

https://github.com/ruby/strscan/commit/a9340ab377

(https://github.com/ruby/strscan/pull/129)

s/begining/beginning/

https://github.com/ruby/strscan/commit/734b823463

(https://github.com/ruby/strscan/pull/126)

Split off from https://github.com/ruby/ruby/pull/12322

https://github.com/ruby/strscan/commit/9bee37e0f5

(https://github.com/ruby/strscan/pull/123)

Added support for string pattern type in
https://github.com/ruby/strscan/pull/106.
And fix Success Return content.

https://github.com/ruby/strscan/commit/6a5acde674

(https://github.com/ruby/strscan/pull/112)

See current doc, search for '## Target Substring', notice the backtick
that isn't visible to the GitHub md parser.

https://github.com/ruby/strscan/blob/843e931d134b0a8f0284296250454374e3f8a6aa/doc/strscan/strscan.md

Fixed in the PR, see:

https://github.com/MSP-Greg/strscan/blob/00-strscan.md/doc/strscan/strscan.md

https://github.com/ruby/strscan/commit/041b15df4c

https://github.com/ruby/strscan/pull/99 split document with multi-byte
chars.