Upadated readthedocs conf file and added dedicated Sphinx requirements.

.readthedocs.yml

@@ -1,14 +1,13 @@
 version: 2
 
-# Build documentation in the docs/ directory with Sphinx
 sphinx:
    configuration: docs/conf.py
 
-# Set the version of Python and requirements required to build your docs
+build:
+  os: ubuntu-20.04
+  tools:
+    python: "3.12"
+
 python:
-  version: 3.7
   install:
-    - requirements: requirements.txt
-    - method: pip
-      path: .
-  system_packages: true
+    - requirements: requirements_sphinx.txt

requirements_sphinx.txt

@@ -0,0 +1,19 @@
+Keras >=2.1.3, <3.0.0
+matplotlib >=2.1.2, <4.0.0
+numpy >=1.19.5, <2.0.0
+scikit-learn >=0.2.2, <2.0.0
+pandas >=0.23.4, <2.0.0
+chardet >=3.0.4, <4.0.0
+convertdate >=2.1.2, <3.0.0
+lunarcalendar >=0.0.9, <1.0.0
+cython >=0.29.17, <1.0.0
+requests >=2.20.0, <3.0.0
+h5py >=2.10.0, <4.0.0
+scipy >=1.5.4, <2.0.0
+pyppeteer >=0.2.6, <1.0.0
+propertime>=1.0.0, < 2.0.0
+fitter==1.7.0
+
+sphinx==5.3.0
+sphinx_rtd_theme==1.1.1
+sphinx-notfound-page==1.0.2