Record Type

# Record

Record allows you to create simple object bag definitions taking in two generic arguments (key and value).

As an example, at a simple level `Record` is same as `{[key:string]:string}`.

However because of the placement of the generic argument it can help with creating typesafe maps very conveniently e.g. `Record`. You can do the equivalent with mapped types i.e. `{ [P in Something]: string }` but the record version reads easier :rose:

Start by locating the book section where TypeScript object, generic, or mapped types are documented; the issue provides the Record examples to use as context. Add a concise explanation of Record and its mapped-type equivalent, then verify that the new documentation fits the surrounding section and examples.

Written by the indexing model from the issue text.