request #7025: Remove old programmer-guide

For now, the programmer guide is deported into the Tuleap documentation.
So, we can removed this old version that was outdated

Change-Id: I80dfe73b4439aa629d7bcb4cd59ac70904dd4c4f
Merge commit 'refs/changes/07/2607/2' of ssh://gerrit.tuleap.net:29418/tuleap into stable

* ssh://gerrit.tuleap.net:29418/tuleap:
  request #7025: Remove old programmer-guide
This is Tuleap 7.1.99.22

Change-Id: I84242ce7f46d78d9a064a3a91690283086fb2f3a