fix heading levels

Author: katiegoines

src/fragments/lib/auth/common/mfa/add_mfa.mdx

@@ -1,4 +1,4 @@
-#### SMS MFA
+### SMS MFA
 ```bash
 $ amplify add auth
 
@@ -21,7 +21,7 @@ Some next steps:
 "amplify publish" will build all your local backend and frontend resources (if you have hosting category added) and provision it in the cloud
 ```
 
-#### TOTP MFA
+### TOTP MFA
 ```bash
 $ amplify add auth
 
@@ -40,4 +40,4 @@ $ amplify add auth
 Some next steps:
 "amplify push" will build all your local backend resources and provision it in the cloud
 "amplify publish" will build all your local backend and frontend resources (if you have hosting category added) and provision it in the cloud
-```
+```

src/fragments/lib/auth/common/mfa/update_mfa.mdx

@@ -3,7 +3,7 @@ The following steps show how to enable MFA as "Optional" for users. In this mode
 
 If you'd like to make MFA required for users, you must first delete your auth resource by running `amplify remove auth`, then follow the **New Project** flow on this page.
 
-#### SMS MFA
+### SMS MFA
 ```bash
 $ amplify update auth
 
@@ -27,7 +27,7 @@ Some next steps:
 ```
 
 
-#### TOTP MFA
+### TOTP MFA
 ```bash
 $ amplify update auth
 
@@ -46,4 +46,4 @@ $ amplify update auth
 Some next steps:
 "amplify push" will build all your local backend resources and provision it in the cloud
 "amplify publish" will build all your local backend and frontend resources (if you have hosting category added) and provision it in the cloud
-```
+```