Slurm submission and execution

• add Slurm documentation (currently based on CS only)
• fix legacy tar bomb
• update main EasyBuild documentation
  • fix broken links
  • rewrite examples to use currently existing easyconfigs

assigned to @opr0019

added 38 commits

• a3d9ea92...9449a4e8 - 37 commits from branch master
• 743c0d16 - Merge branch 'master' into 'slurm-submission-and-execution'

Compare with previous version

mentioned in commit 3b553a41

merged