reverted to old readme.rst to avoid wierd error

3 jobs for master in 1 minute and 8 seconds (queued for 2 seconds)
Status Job ID Name Coverage
  Test
passed #8752
orphans

00:00:12

failed #8753
pages

00:00:38

passed #8751
spelling

00:00:17

 
Name Stage Failure
failed
pages Test There is an unknown failure, please try again
  File "/usr/local/lib/python3.6/logging/__init__.py", line 719, in filter
result = f.filter(record)
File "/usr/local/lib/python3.6/site-packages/sphinx/util/logging.py", line 426, in filter
raise SphinxWarning(location + ":" + message)
sphinx.errors.SphinxWarning: /builds/mackernan/E-CAM-Library/Classical-MD-Modules/modules/PIcore/readme.rst:5:duplicate label particle_insertion_core, other instance in /builds/mackernan/E-CAM-Library/Classical-MD-Modules/modules/PIcore/OLDreadme.rst

Warning, treated as error:
/builds/mackernan/E-CAM-Library/Classical-MD-Modules/modules/PIcore/readme.rst:5:duplicate label particle_insertion_core, other instance in /builds/mackernan/E-CAM-Library/Classical-MD-Modules/modules/PIcore/OLDreadme.rst
ERROR: Job failed: exit code 1