Nesting selector support

Hi, in a browser you can use the & selector to write a query relative to the node in question:

let temp0 = document.querySelector(".someClass");
temp0.querySelectorAll("& > ul > li"); // matches only direct descendants of the .someClass node

... but it seems like css-select does not support this:

let machineSection = select(root, "li:has(> #idx2D70)");
// ...
let manufacturerSections = selectAll(machineSection, "& > ul > li");  // throws error, see below
// ...

Error: Empty sub-selector
    at finalizeSubselector (/home/sven/projects/seekseek/config-v2/node_modules/.pnpm/css-what@7.0.0/node_modules/css-what/dist/commonjs/parse.js:216:19)
    at parseSelector (/home/sven/projects/seekseek/config-v2/node_modules/.pnpm/css-what@7.0.0/node_modules/css-what/dist/commonjs/parse.js:487:5)
    at parse (/home/sven/projects/seekseek/config-v2/node_modules/.pnpm/css-what@7.0.0/node_modules/css-what/dist/commonjs/parse.js:130:22)
    at _compileUnsafe (/home/sven/projects/seekseek/config-v2/node_modules/.pnpm/css-select@6.0.0/node_modules/css-select/dist/commonjs/index.js:85:78)
    at Object.select (/home/sven/projects/seekseek/config-v2/node_modules/.pnpm/css-select@6.0.0/node_modules/css-select/dist/commonjs/index.js:97:21)
    ...

With the nesting selector having baseline availability now, do you intend to support this in css-select as well?

Start with the select and selectAll entry points shown in the example, then reproduce the nesting-selector failure and follow the parser/compiler path named in the stack trace. Check how the selector is parsed and compiled relative to the queried node. Done means selectors beginning with & work for the demonstrated direct-child query without throwing an empty-sub-selector error.