fixed docutils version, added comments, and minor update in a notebook

Author: AleksMat

examples/session_sharing.ipynb

@@ -275,8 +275,11 @@
     "\n",
     "1. Create a single authentication session.\n",
     "2. Start a separate thread that is continuously running the following 2-step procedure:\n",
+    "   \n",
     "   * extract a session token and send it to a shared memory space,\n",
     "   * wait until the current session token is close to expiring and the token will have to be refreshed.\n",
+    "\n",
+    "\n",
     "3. Start parallelization with multiple Python processes.\n",
     "4. Each process should read the token from the shared memory space and cache it into its client object every time before it starts interacting with Sentinel Hub service.\n",
     "\n",

requirements-docs.txt

@@ -1,9 +1,8 @@
-jupyter_core
-docutils
 sphinx
 sphinx_rtd_theme
 nbsphinx
 matplotlib
 ipython
 m2r2
-jinja2==3.0.3
+docutils==0.17.1  # Newer versions don't format lists correctly on some browsers when run on ReadTheDocs
+jinja2==3.0.3  # Newer versions aren't compatible with nbsphinx==0.8.8