[ledger] Update documentation on directory organization.

Test: Nothing, only documentation is updated.
Change-Id: I01c47eb3764d6c31cf59a3e3f69956216b57c95f
diff --git a/bin/ledger/app/ledger_repository_factory_impl.cc b/bin/ledger/app/ledger_repository_factory_impl.cc
index 4e4c11c..5682137 100644
--- a/bin/ledger/app/ledger_repository_factory_impl.cc
+++ b/bin/ledger/app/ledger_repository_factory_impl.cc
@@ -42,7 +42,7 @@
 
 // The contents of each repository are organized in the following way:
 //   <base_path>
-//   ├── <serialization-version>
+//   ├── <serialization_version>
 //   │   ├── name
 //   │   ├── cache/
 //   │   ├── page_usage_db/
@@ -53,16 +53,19 @@
 // - <base_path>/
 //   The base path of this repository. It is defined by the channel given in
 //   |LedgerRepositoryFactory::GetRepository| (see the internal.fidl API).
-// - <base_path>/content/
-//   Contains all the contents of this repository. It is used to store the
-//   `name` file, `page_usage_db/` (see below), and is also used by
-//   |LedgerRepositoryImpl| to store this repository's Ledger instances.
-// - <base_path>/content/name
+// - <base_path>/<serialization_version>/
+//   Stores all the contents of this repository for that serialization
+//   version. It is used to store the `name` file, and subdirectories `cache/`,
+//   `page_usage_db/` and `ledgers/` (see below).
+// - <base_path>/<serialization_version>/name
 //   Stores the name of the repository, which is randomly chosen on creation.
-// - <base_path>/content/cache/
+// - <base_path>/<serialization_version>/cache/
 //   The path used by |LevelDbFactory| as the cache directory.
-// - <base_path>/content/page_usage_db/
+// - <base_path>/<serialization_version>/page_usage_db/
 //   The path used by |DiskCleanupManagerImpl| to store statistics on pages.
+// - <base_path>/<serialization_version>/ledgers/
+//   The path used by |LedgerRepositoryImpl| to store all Ledger instances for
+//   this repository.
 // - <base_path>/staging/
 //   The staging path. Used for removing all contents of this repository.
 //
diff --git a/docs/ledger/data_in_storage.md b/docs/ledger/data_in_storage.md
index 6c9cfbb..c356228 100644
--- a/docs/ledger/data_in_storage.md
+++ b/docs/ledger/data_in_storage.md
@@ -13,7 +13,7 @@
 All data and metadata added in storage are persisted using LevelDB. For each
 [page](data_organization.md#Pages) a separate LevelDB instance is created in a
 dedicated filesystem path of the form:
-`{repo_dir}/content/{ledger_dir}/{page_id_base64}/leveldb`.
+`{repo_dir}/{serialization_version}/ledgers/{ledger_dir}/{page_id_base64}/leveldb`.
 
 Additionally, metadata about all pages of a single user are persisted in a
 separate LevelDB instance. This includes information such as the last time a