[SDC-DIST-CLIENT] Add new RTD entry

Update README etc

Signed-off-by: efiacor <fiachra.corcoran@est.tech>
Change-Id: I4f92684e82d3fc2df978af12100be0871b94178d
Issue-ID: DMAAP-1792
diff --git a/docs/tox.ini b/docs/tox.ini
index edac8c3..6e1245c 100644
--- a/docs/tox.ini
+++ b/docs/tox.ini
@@ -1,22 +1,32 @@
 [tox]
 minversion = 1.6
-envlist = docs,
+envlist = docs,docs-linkcheck,docs-spellcheck
 skipsdist = true
 
 [testenv:docs]
-basepython = python3
-deps = -r{toxinidir}/requirements-docs.txt
+basepython = python3.8
+deps =
+    -r{toxinidir}/requirements-docs.txt
+    -chttps://raw.githubusercontent.com/openstack/requirements/stable/yoga/upper-constraints.txt
+    -chttps://git.onap.org/doc/plain/etc/upper-constraints.onap.txt?h=master
 commands =
-    sphinx-build -b html -n -d {envtmpdir}/doctrees ./ {toxinidir}/_build/html
-    echo "Generated docs available in {toxinidir}/_build/html"
-whitelist_externals =
-    echo
-    git
-    sh
+    sphinx-build -W -q -b html -n -d {envtmpdir}/doctrees {toxinidir} {toxinidir}/_build/html
 
 [testenv:docs-linkcheck]
-basepython = python3
-#deps = -r{toxinidir}/requirements-docs.txt
-commands = echo "Link Checking not enforced"
-#commands = sphinx-build -b linkcheck -d {envtmpdir}/doctrees ./ {toxinidir}/_build/linkcheck
-whitelist_externals = echo
+basepython = python3.8
+deps =
+    -r{toxinidir}/requirements-docs.txt
+    -chttps://raw.githubusercontent.com/openstack/requirements/stable/yoga/upper-constraints.txt
+    -chttps://git.onap.org/doc/plain/etc/upper-constraints.onap.txt?h=master
+commands =
+    sphinx-build -W -q -b linkcheck -d {envtmpdir}/doctrees {toxinidir} {toxinidir}/_build/linkcheck
+
+[testenv:docs-spellcheck]
+basepython = python3.8
+deps =
+    -r{toxinidir}/requirements-docs.txt
+    -chttps://raw.githubusercontent.com/openstack/requirements/stable/yoga/upper-constraints.txt
+    -chttps://git.onap.org/doc/plain/etc/upper-constraints.onap.txt?h=master
+commands =
+    sphinx-build -W -q -b spelling -d {envtmpdir}/doctrees {toxinidir} {toxinidir}/_build/spellcheck
+