administration: configuring-fluent-bit: multiline-parsing: update documentation with missing features and add examples (#2278)

* administration: configuring-fluent-bit: multiline-parsing: update documentation with missing features and add examples

Update multiline parsing documentation based on fluent-bit source code:

Configuration updates:
- Add missing `ruby` built-in multiline parser
- Document additional type values: `endswith` and `equal`/`eq`
- Add missing properties: `negate` and `match_string`
- Fix `flush_timeout` default from 5s to 4s (matches source)
- Fix `multiline_buffer_limit` default from 2MiB to 2MB
- Clarify that KB/MB/GB and KiB/MiB/GiB suffixes are all interpreted as binary
- Sort configuration properties table alphabetically

Add built-in parser examples section:
- Add comprehensive examples for all 6 built-in parsers:
  cri, docker, go, java, python, ruby
- Include YAML and classic configuration for each parser
- Show input log samples and expected output after concatenation
- Add subsection headers for better navigation

Fixes #2276.

Signed-off-by: Eric D. Schabell <[email protected]>

* administration: configuring-fluent-bit: multiline-parsing: fixed linting issue.

Signed-off-by: Eric D. Schabell <[email protected]>

* administration: configuring-fluent-bit: multiline-parsing: fixed more linting issue.

Signed-off-by: Eric D. Schabell <[email protected]>

* administration: configuring-fluent-bit: multiline-parsing: fixed for review comment.

Signed-off-by: Eric D. Schabell <[email protected]>

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Signed-off-by: Eric D. Schabell <[email protected]>

Author: eschabell