Add syntax templating to mcdoc

[MulverineX]

When defining types, autocomplete should immediately appear with predefined template/code snippet options.

Example:

dispatch minecraft:resource[pack] to struct Pack {
    pack: struct {
        #[pack_format]
        pack_format: (
            (int @ 1..) |
            (#[default] 47) |
        ),
        description: Text,
    },
    #[since=1.19]
    filter?: PackFilter,
    #[since="1.19.3"]
    features?: PackFeatures,
}

1. User creates data folder
2. Creates & opens pack.mcmeta
3. Presented with template autocomplete
4. Hits tab, is prompted to fill in required fields, can tab complete to #[default] values.

[SPGoding]

can we infer the template from the normal type definition? maybe even with #[default] attributes on individual fields for the placeholder values. i don't see the point of repeating so much information with a weird #[template] attribute.

[MulverineX]

I guess someone could still do something like this after inject is introduced, if #[default] was added:

use ::java::server::world::entity::display::DisplayBase

inject DisplayBase::transformation::__union to (#[default] [1f,0f,0f,0f,0f,1f,0f,0f,0f,0f,1f,0f,0f,0f,0f,1f])

[MulverineX]

Modified the initial suggestion