Function upsertManagedBlock

upsertManagedBlock(
    fileContent: string,
    markers: ManagedMarkers,
    body: string,
    stamp: ManagedBlockStampOptions,
): string
Insert or replace the managed block in file content.
Parameters
- fileContent: string
  Existing file content (empty string for a new file).
- markers: ManagedMarkers
  Marker set.
- body: string
  Managed body (Markdown).
- stamp: ManagedBlockStampOptions
  Version stamp options.
Returns string
The new file content.

Remarks
If a block with these markers exists, it is replaced in place. Otherwise the block is inserted at markers.position (default 'top'), and any orphaned BEGIN marker of the same type is stripped from user content so it cannot pair with the new END marker later.
- Defined in managed/managedBlock.ts:98