README: add example output

Author: gmta

README.md

@@ -30,3 +30,15 @@ try (InputStream is = new BufferedInputStream(Files.newInputStream(streamFile));
     e.printStackTrace();
 }
 ```
+
+Example output:
+
+```
+BtrfsStreamHeader{version=1}
+BtrfsSnapshotCommand{header=BtrfsCommandHeader{length=79 command=SNAPSHOT crc=6ba462e6} path='my-snapshot' UUID=d671a994-8e64-c14b-b73d-6eee6fdf21db CTransID=1081204 cloneUUID=6e61cd26-0fe5-f84d-85df-8d6fb67f3cc8 cloneCTransID=1081185}
+BtrfsWriteCommand{header=BtrfsCommandHeader{length=49185 command=WRITE crc=a5dcaab3} path='folder/file.dat' fileOffset=0 data=[49152 bytes]}
+BtrfsUTimesCommand{header=BtrfsCommandHeader{length=65 command=UTIMES crc=b72bba65} path='folder/file.dat' atime=BtrfsTimespec{seconds=1521381730 nanoSeconds=631324600 : 2018-03-18T14:02:10.6313246Z} ctime=BtrfsTimespec{seconds=1522406824 nanoSeconds=308205750 : 2018-03-30T10:47:04.30820575Z} mtime=BtrfsTimespec{seconds=1522406824 nanoSeconds=308205750 : 2018-03-30T10:47:04.30820575Z}}
+BtrfsChownCommand{header=BtrfsCommandHeader{length=94 command=CHOWN crc=af28f1c5} path='folder/file.dat' uid=8 gid=8}
+BtrfsChmodCommand{header=BtrfsCommandHeader{length=82 command=CHMOD crc=f5e23d04} path='folder/file.dat' mode=660}
+BtrfsEndCommand{header=BtrfsCommandHeader{length=0 command=END crc=9dc96c50}}
+```