DOC: Splitting api.rst in several files (#24462)

Author: datapythonista

.gitignore

@@ -101,6 +101,7 @@ asv_bench/pandas/
 # Documentation generated files #
 #################################
 doc/source/generated
+doc/source/api/generated
 doc/source/_static
 doc/source/vbench
 doc/source/vbench.rst

doc/make.py

@@ -183,7 +183,7 @@ def clean():
         Clean documentation generated files.
         """
         shutil.rmtree(BUILD_PATH, ignore_errors=True)
-        shutil.rmtree(os.path.join(SOURCE_PATH, 'generated'),
+        shutil.rmtree(os.path.join(SOURCE_PATH, 'api', 'generated'),
                       ignore_errors=True)
 
     def zip_html(self):