change some doc file names

upstream rst files kept in the project subdirectory which not meet the
requirement of OPNFV(in docs/).

issues in
https://build.opnfv.org/ci/job/docs-verify-rtd-master/1590/console may be
caused by parser project

Change-Id: I096b84d76e7aba1bea181e640eb2e3710a779d3c
Signed-off-by: Julien <zhang.jun3g@zte.com.cn>

diff --git a/tosca2heat/heat-translator/CONTRIBUTING.rst b/tosca2heat/heat-translator/CONTRIBUTING.md
similarity index 100%
rename from tosca2heat/heat-translator/CONTRIBUTING.rst
rename to tosca2heat/heat-translator/CONTRIBUTING.md

diff --git a/tosca2heat/heat-translator/HACKING.rst b/tosca2heat/heat-translator/HACKING.md
similarity index 100%
rename from tosca2heat/heat-translator/HACKING.rst
rename to tosca2heat/heat-translator/HACKING.md

diff --git a/tosca2heat/tosca-parser/CONTRIBUTING.rst b/tosca2heat/tosca-parser/CONTRIBUTING.md
similarity index 100%
rename from tosca2heat/tosca-parser/CONTRIBUTING.rst
rename to tosca2heat/tosca-parser/CONTRIBUTING.md

diff --git a/tosca2heat/tosca-parser/HACKING.rst b/tosca2heat/tosca-parser/HACKING.md
similarity index 100%
rename from tosca2heat/tosca-parser/HACKING.rst
rename to tosca2heat/tosca-parser/HACKING.md