Undocumented fields

As reported by @iamOgunyinka, in the [specs](https://www.adobe.com/devnet-apps/photoshop/fileformatashtml/#50577411_21585) some items in the Reference Structure are not documented:

```
'Idnt' = Identifier
'indx' = Index
'name' = Name
```

We have to find some extra documentation to be able to read or skip this information, or reverse engineering them. E.g. maybe 'name' is just a Unicode string.

Start with the linked Adobe Photoshop file-format specification and inspect the library's handling of the Reference Structure. Determine whether the Idnt, indx, and name fields can be documented, read, or safely skipped; completion requires resolving their meaning or documenting their handling, but no source file or test is named.

Written by the indexing model from the issue text.