lib: more cache fixes

Closes nodejs#3806

Signed-off-by: flakey5 <73616808+flakey5@users.noreply.github.com>

docs/docs/api/CacheStore.md

@@ -21,7 +21,7 @@ The store must implement the following functions:
 
 ### Getter: `isFull`
 
-This tells the cache interceptor if the store is full or not. If this is true,
+Optional. This tells the cache interceptor if the store is full or not. If this is true,
 the cache interceptor will not attempt to cache the response.
 
 ### Function: `createReadStream`
@@ -30,18 +30,18 @@ Parameters:
 
 * **req** `Dispatcher.RequestOptions` - Incoming request
 
-Returns: `CacheStoreReadable | Promise<CacheStoreReadable | undefined> | undefined` - If the request is cached, a readable for the body is returned. Otherwise, `undefined` is returned.
+Returns: `Readable | Promise<Readable | undefined> | undefined` - If the request is cached, a readable for the body is returned. Otherwise, `undefined` is returned.
 
 ### Function: `createWriteStream`
 
 Parameters:
 
 * **req** `Dispatcher.RequestOptions` - Incoming request
-* **value** `CacheStoreValue` - Response to store
+* **value** `CachedResponse` - Response to store
 
-Returns: `CacheStoreWriteable | undefined` - If the store is full, return `undefined`. Otherwise, return a writable so that the cache interceptor can stream the body and trailers to the store.
+Returns: `Writable | undefined` - If the store is full, return `undefined`. Otherwise, return a writable so that the cache interceptor can stream the body and trailers to the store.
 
-## `CacheStoreValue`
+## `CachedResponse`
 
 This is an interface containing the majority of a response's data (minus the body).
 
@@ -57,10 +57,6 @@ This is an interface containing the majority of a response's data (minus the bod
 
 `(Buffer | Buffer[])[]` - The response's headers.
 
-### Property `rawTrailers`
-
-`string[] | undefined` - The response's trailers.
-
 ### Property `vary`
 
 `Record<string, string> | undefined` - The headers defined by the response's `Vary` header
@@ -96,20 +92,6 @@ is either the same sa staleAt or the `max-stale` caching directive.
 
 The store must not return a response after the time defined in this property.
 
-## `CacheStoreReadable`
-
-This extends Node's [`Readable`](https://nodejs.org/api/stream.html#class-streamreadable)
-and defines extra properties relevant to the cache interceptor.
-
-### Getter: `value`
-
-The response's [`CacheStoreValue`](#cachestorevalue)
-
-## `CacheStoreWriteable`
-
-This extends Node's [`Writable`](https://nodejs.org/api/stream.html#class-streamwritable)
-and defines extra properties relevant to the cache interceptor.
-
 ### Setter: `rawTrailers`
 
 If the response has trailers, the cache interceptor will pass them to the cache