Since they'd be something other than just MWE code examples, are those posted here or, say, on CTAN?
I have made this into an answer as it would be to long otherwise and deleted my comments on the question.
I guess you are referring to information like https://ctan.org/pkg/pgf.
If a package is distributed by the three distributions
proTeXt, then you usually find the documentation on CTAN and the distribution itself (i.e you have a copy of the files on your hard drive). These three distributions cover the most important operating systems and I recommend using one of these. Naturally, you will not find information on "external" packages. As @Skillmon has pointed out, CTAN "is only" the host and the package/class authors "have" to provide information on themselves.
I am certainly not an expert as I have never uploaded anything. Others probably could contribute more. You should find basic information on https://ctan.org/file/help/ctan/CTAN-upload-addendum. If you think you have anything worth contributing I would publish it on CTAN which imho is the standard source. CTAN also features documents which are not classical documentations of packages or classes like https://ctan.org/pkg/happy4th and https://ctan.org/pkg/lshort-english.
There are some entries like https://tex.stackexchange.com/a/68740/128553 on this site which I would wish to be packages on ctan, but they are not. You can also post a topic on this site and upload your solution as an answer on this site to share it with the world. Needless to say, that there are other community pages like http://www.texample.net which offer good solutions, not all of those community pages are in English.
I would like to add another perspective on one of Skillmon's comments below. We do not know the number of people who do read the manual and find solutions to their problems by themselves, thus simple questions on this site might give the impression that many people do not read the manuals. On the other hand, users might not find what they looking for because the do not exactly know what to look for or where to look for. If you do not know the name of the concept you are looking for, you might not be able to find the fitting packages or the the relevant two sentences in a large documentation.
Writing good on complex software documentation for alle stakeholders is a difficult task and comes with various problems which apply to non-
TeX-related software, too.