add 8GB to memory option doc (#1129)

Co-authored-by: Yamahitsuji <yagi.yusei@classmethod.jp>

Author: yamahitsuji

src/function-builder.ts

@@ -277,7 +277,7 @@ export function region(
  * Configure runtime options for the function.
  * @param runtimeOptions Object with optional fields:
  * 1. `memory`: amount of memory to allocate to the function, possible values
- *    are: '128MB', '256MB', '512MB', '1GB', '2GB', and '4GB'.
+ *    are: '128MB', '256MB', '512MB', '1GB', '2GB', '4GB', and '8GB'.
  * 2. `timeoutSeconds`: timeout for the function in seconds, possible values are
  *    0 to 540.
  * 3. `failurePolicy`: failure policy of the function, with boolean `true` being
@@ -321,7 +321,7 @@ export class FunctionBuilder {
    * Configure runtime options for the function.
    * @param runtimeOptions Object with optional fields:
    * 1. `memory`: amount of memory to allocate to the function, possible values
-   *    are: '128MB', '256MB', '512MB', '1GB', '2GB', and '4GB'.
+   *    are: '128MB', '256MB', '512MB', '1GB', '2GB', '4GB', and '8GB'.
    * 2. `timeoutSeconds`: timeout for the function in seconds, possible values are
    *    0 to 540.
    * 3. `failurePolicy`: failure policy of the function, with boolean `true` being