fix doc config files

Issue-ID: DOC-798

Signed-off-by: thmsdt <thomas.kulik@telekom.de>
Change-Id: I5d49c5f546e4f54bd1924fdcd2e6d7282b4eb20e
diff --git a/docs/requirements-docs.txt b/docs/requirements-docs.txt
index 3b3441a..e992682 100644
--- a/docs/requirements-docs.txt
+++ b/docs/requirements-docs.txt
@@ -1,3 +1,8 @@
-lfdocs-conf
 sphinx>=4.2.0  # BSD
 sphinx-rtd-theme>=1.0.0  # MIT
+sphinxcontrib-blockdiag  # BSD
+sphinxcontrib-seqdiag # BSD
+sphinxcontrib-swaggerdoc
+sphinxcontrib-spelling
+sphinxcontrib-plantuml
+sphinx-tabs