Add missing ext/operator documentation

[jb-lopez]

This pull request is to add the missing documentation for the PECL operator extension. I have taken over as the lead maintainer for that extension, but this is my first contribution to the PHP documentation so any feedback is welcome. There is a companion pull request to doc-base that goes with one and is required by this one. php/doc-base#246

There appears to never have been any documentation for the PECL operator extension. For this pull request I've added the test class that ext/operator uses all of its overloading capabilities as a complete code sample.

[jb-lopez]

I would like to note that since this is a new documentation the workflow run https://github.com/php/doc-en/actions/runs/14958493251/job/42050000015 is going to fail until the related pull request php/doc-base#246 is merged.

[bettykadondi12]

Great👍

[jordikroon]

Suggested change

	<para>
	Using the above class, you can overload the operators as follows:
	</para>
	<simpara>
	Using the above class, you can overload the operators as follows:
	</simpara>

[jordikroon]

Suggested change

	<para>
	The above code will output:
	</para>
	<simpara>
	The above code will output:
	</simpara>

[jordikroon]

Suggested change

	<para>
	&pecl.info;
	<link xlink:href="&url.pecl.package;operator">&url.pecl.package;operator</link>.
	</para>
	<simpara>
	&pecl.info;
	<link xlink:href="&url.pecl.package;operator">&url.pecl.package;operator</link>.
	</simpara>

[jordikroon]

Suggested change

	operator releases are hosted by PECL and the source code by
	<link xlink:href="&url.git.hub;jb-lopez/pecl-php-operator">github</link>.
	Operator releases are hosted by PECL and the source code by
	<link xlink:href="&url.git.hub;jb-lopez/pecl-php-operator">Github</link>.

[jordikroon]

Could you register this as a global entity in doc-base? global.ent file.
Also PECL is deprecated. It is preferred to use PIE. So I would even suggest to strongly encourage users to install this extension through PIE.

https://github.com/php/pie

[jordikroon]

Suggested change

	<para>
	The following is the class that is used in the testing of the operator overloading extension.
	It overloads all of the possible operators that can be overloaded for testing.
	</para>
	<simpara>
	This class provides implementations for all operators that can be overloaded
	by the operator overloading extension. It is intended as a reference class for
	users who want to see which overloadable operators are available and how they
	are represented.
	</simpara>