added cvxpy to documentation requirements so all methods get imported for docs build

Author: pavelkomarov

README.md

@@ -9,8 +9,8 @@ Python methods for numerical differentiation of noisy data, including multi-obje
 </p>
 
 <p align="center">
-    <a href='https://pynumdiff.readthedocs.io/en/master/?badge=master'>
-        <img src='https://readthedocs.org/projects/pynumdiff/badge/?version=master' alt='Documentation Status' /></a>
+    <a href='https://pynumdiff.readthedocs.io/master/'>
+        <img src='https://app.readthedocs.org/projects/pynumdiff/badge/?version=master' alt='Documentation Status' /></a>
     <a href="https://badge.fury.io/py/pynumdiff">
         <img src="https://badge.fury.io/py/pynumdiff.svg" alt="PyPI version" height="18"></a>
     <a href="https://zenodo.org/badge/latestdoi/159711175">

pyproject.toml

@@ -48,7 +48,8 @@ dev = [
 ]
 docs = [
     "sphinx",
-    "sphinx_rtd_theme"
+    "sphinx_rtd_theme",
+    "cvxpy"
 ]
 
 [tool.setuptools_scm]