reorder the primitives list and improve a few titles (#3640)

diff --git a/docs/hazmat/primitives/index.rst b/docs/hazmat/primitives/index.rst
index 022cb9f..78beb3d 100644
--- a/docs/hazmat/primitives/index.rst
+++ b/docs/hazmat/primitives/index.rst
@@ -6,12 +6,12 @@
 .. toctree::
     :maxdepth: 1
 
-    cryptographic-hashes
-    mac/index
-    symmetric-encryption
-    padding
-    key-derivation-functions
-    keywrap
     asymmetric/index
     constant-time
+    key-derivation-functions
+    keywrap
+    mac/index
+    cryptographic-hashes
+    symmetric-encryption
+    padding
     twofactor