Clarify examples folder names

[mk-pmb]

Hi! The current example subfolders "client" and "server" make it look like this would be a client/server application. From the code it looks more like the "client" scripts are meant to run in web browsers, so how about we rename that folder to "web" or "html" or "browser-native"?

The "server" scripts seem meant to be run in a CommonJS environment such as Node.js, so how about we name that folder "cjs"? I recommend not to use "cli" or "node", because there are frameworks that enable browsers to load CommonJS modules (no build step required).