Added tests for search module.

Changed import approach - changed from relative path imports to package imports. In general it is preferrable approach.

Reverted single change: it have to be
const delimiters = switch (builtin.target.os.tag) {
.windows => " \r\n\t",
else => " \n\t",
};
It seems to me like accidental change, but I may be wrong - please let me know if I'm wrong.

Thank u for developing project.