add req.txt for RTD

docs/requirements.txt

@@ -1 +1,38 @@
-argser
+alabaster==0.7.12
+atomicwrites==1.3.0
+attrs==19.2.0
+Babel==2.7.0
+certifi==2019.9.11
+chardet==3.0.4
+coverage==4.5.4
+docutils==0.15.2
+idna==2.8
+imagesize==1.1.0
+importlib-metadata==0.23
+Jinja2==2.10.3
+m2r==0.2.1
+MarkupSafe==1.1.1
+mistune==0.8.4
+more-itertools==7.2.0
+packaging==19.2
+pbr==5.4.3
+pluggy==0.13.0
+py==1.8.0
+Pygments==2.4.2
+pyparsing==2.4.2
+pytz==2019.3
+requests==2.22.0
+six==1.12.0
+snowballstemmer==2.0.0
+Sphinx==2.2.0
+sphinx-rtd-theme==0.4.3
+sphinxcontrib-apidoc==0.3.0
+sphinxcontrib-applehelp==1.0.1
+sphinxcontrib-devhelp==1.0.1
+sphinxcontrib-htmlhelp==1.0.2
+sphinxcontrib-jsmath==1.0.1
+sphinxcontrib-qthelp==1.0.2
+sphinxcontrib-serializinghtml==1.1.3
+urllib3==1.25.6
+wcwidth==0.1.7
+zipp==0.6.0