Is wiki.js suitable for developing public wiki (would be a specific topic) available online? It is considered a small project, however, search function should be a must also.
I will be the only developer, I am more .NET/C# developer, but I have no problems with js also (so node.js could be ok). However, I do not have any experience with markdowns and MongoDB. Also, I do not know is it easy to find hosting for node.js + git (as it is necessary, right)?
Yes, wiki.js is perfectly suitable for hosting a basic wiki online. Wiki.js is currently in its 1.0 build which is relatively limited in its functionality however. The 2.0 beta is looking much more promising for large scale deployments. If you want to make a wiki for hundreds of people, you should use something like MediaWiki.
Both the 1.0 and the 2.0 builds have a search function out of the box.
The 1.0 build only requires you to install the latest version of MongoDB, the configuration is handled by the application. You merely need to follow the instructions for installation at https://docs.requarks.io/wiki/install/installation If you consider yourself a developer, you should learn markdown, it's very simple and widely used.
Yes, node.js is absolutely necessary. In the 1.0 build, a git repo is how you backup and sync all your pages for the wiki. Technically you don't need it, but it's great for backing up files if you ever need to move the wiki to new hosting for example. For hosting, any vm will work. I would recommend using a cloud provider like Google Cloud Platform or Amazon Web Services. It's easy to learn and quick to set up. Start a GCP trial for 300 days, start an SSH session, install all the dependencies, set up a repo, and follow the installation instructions on the docs website for wiki.js. It should be a simple process if you follow the instructions. Cheers.