add function parameter names to generated docs

[andrewrk]

std lib example: file:///home/andy/dev/zig/build/zig-cache/docs/index.html#std;io.readFileAlloc (I recognize this is a file:/// URL; we don't have #3402 done yet)

it shows:

fn readFileAlloc(*mem.Allocator, []const u8) ![]u8

but it should show:

fn readFileAlloc(allocator: *mem.Allocator, path: []const u8) ![]u8

I would also like to propose the following rule:

• when a parameter name is its type name lower cased, the parameter name is omitted.

That would further adjust the expected docs to be:

fn readFileAlloc(*mem.Allocator, path: []const u8) ![]u8

[ikskuh]

when a parameter name is its type name lower cased, the parameter name is omitted.

This is a great idea! Sometimes the type is documentation enough about how to use a certain parameter. Especially for something like *std.mem.Allocator the use in the Zig language is quite clear and thus removes clutter from the documentation.

[andrewrk]

Thanks @FireFox317 for the implementation of this! I added the part about omitting parameter names that match the type.