Attempt to import sphixcontrib-spelling, if fails pass

Author: FabioRosado

doc/source/conf.py

@@ -87,8 +87,14 @@
 
 exclude_patterns = ['**.ipynb_checkpoints']
 
-spelling_word_list_filename = ['spelling_wordlist.txt', 'names_wordlist.txt']
-spelling_ignore_pypi_package_names = True
+# Tries to import sphixcontrib.spelling - if not available pass
+try:
+    import sphinxcontrib.spelling
+    extensions.append('sphinxcontrib.spelling')
+    spelling_word_list_filename = ['spelling_wordlist.txt', 'names_wordlist.txt']
+    spelling_ignore_pypi_package_names = True
+except ModuleNotFoundError:
+    pass
 
 with open("index.rst") as f:
     index_rst_lines = f.readlines()