[old.haxe.org] Initialization of static properties

http://old.haxe.org/doc/snip/initialization_of_statics

There is no mention (at least I didn't found it) of the way to initialize static properties in the manual. The method described in the page doesn't seems to work on current haxe version (3.4.7).

EXPECTED:
- Add the corresponding entry in the manual.

Start with the linked old.haxe.org page and compare its static-property initialization method with the behavior of Haxe 3.4.7. Locate the relevant section of the current manual, verify the correct approach with a small example, and add an entry that accurately documents the working method.

Written by the indexing model from the issue text.