document release contributors

```
% ~/code/incubator-pekko/scripts/authors.scala forked-from-akka v1.0.0-RC2
warning: exhaustive rename detection was skipped due to too many files.
warning: you may want to set your diff.renameLimit variable to at least 1222 and retry the command.
Couldn't parse summary section for Stats(Matthew de Detrich,matthew.dedetrich@*****.io,4,5,5,3) 'Fix new sources so that they use the Apache standard header'
commits added removed
86 6002 5157 Johannes Rudolph
85 3448 7588 PJ Fanning
67 129873 117890 Matthew de Detrich
4 226 181 Jan Chyb
4 173 153 Arnout Engelen
2 13644 10541 Auto Format
1 66 6957 Łukasz Sowa
1 119 1389 hughsimpson
1 60 12 Lomig Mégard
1 12 10 Mathias
1 6 0 Jean-Luc Deprez
1 2 1 krrrr38
1 2 0 Keith Wansbrough
1 1 1 kerr
1 1 0 Oliver Trosien
```

Start by reading scripts/authors.scala and reproducing the shown command against the forked-from-akka v1.0.0-RC2 release data. Check how the summary section and contributor statistics are parsed; done should be a documented release-contributor result with the reported parsing problem resolved or clearly handled.

Written by the indexing model from the issue text.