Add the PGA heads docs

Signed-off-by: Vadim Markovtsev <vadim@sourced.tech>

PublicGitArchive/README.md

@@ -8,12 +8,18 @@ This dataset consists of two parts:
 * [Siva](https://github.com/src-d/go-siva) files with Git repositories.
 * Index file in CSV format.
 
+Besides, there is a number of auxiliary datasets:
+
+* [configs.tar.xz](https://drive.google.com/open?id=1_cij4BMrPiKVBVdZyUzg1iOhB3pL6EPR) - raw git config files for each siva.
+* [heads.csv.xz](https://drive.google.com/open?id=136vsGWfIwfd0IrAdfphIU6lkMmme4-Pj) - mapping from HEAD UUID to repository name.
+
 ## Tools
 
 * [pga](pga) - explore the dataset, or download its contents easily.
 * [pga-create](pga-create) - reproduce PGA dataset generation.
 * [borges-indexer](borges-indexer) - exports a CSV file with metadata from repositories fetched with Borges.
 * [pga2uast](pga2uast) - extracts [Babelfish UASTs](https://docs.sourced.tech/babelfish/uast/uast-specification-v2) from the HEADs of siva files.
+* [list_heads](list-pga-heads) - lists files in each HEAD contained in siva.
 
 ## Listing and downloading
 

PublicGitArchive/list-pga-heads/README.md

@@ -35,6 +35,13 @@ For each HEAD inside each siva file, the tool writes the list of file paths. If
 each HEAD is a text file and each file path is on a new line. If the format is "parquet",
 the table schema is two-column ("HEAD name", "file path").
 
+## Results
+
+These are the results of running the tool on PGA'19:
+
+- [configs.tar.xz](https://drive.google.com/open?id=1_cij4BMrPiKVBVdZyUzg1iOhB3pL6EPR) - raw git config files for each siva.
+- [heads.csv.xz](https://drive.google.com/open?id=136vsGWfIwfd0IrAdfphIU6lkMmme4-Pj) - mapping from HEAD UUID to repository name.
+
 ## License
 
-[MIT](https://tldrlegal.com/license/mit-license).
+[MIT](https://tldrlegal.com/license/mit-license).