Fix up some warnings and errors in docs (#817)

* Some lines missing code-block
* Missing blank lines for spacing

Signed-off-by: Eric Brown <[email protected]>

Author: ericwb

bandit/plugins/app_debug.py

@@ -33,7 +33,7 @@
  .. [1] https://flask.palletsprojects.com/en/1.1.x/quickstart/#debug-mode
  .. [2] https://werkzeug.palletsprojects.com/en/1.0.x/debug/
  .. [3] https://labs.detectify.com/2015/10/02/how-patreon-got-hacked-publicly-exposed-werkzeug-debugger/
- .. [4] https://cwe.mitre.org/data/definitions/94.html
+ .. https://cwe.mitre.org/data/definitions/94.html
 
 .. versionadded:: 0.15.0
 

bandit/plugins/snmp_security_check.py

@@ -20,6 +20,7 @@ def snmp_insecure_version_check(context):
     :Example:
 
     .. code-block:: none
+
         >> Issue: [B508:snmp_insecure_version_check] The use of SNMPv1 and
            SNMPv2 is insecure. You should use SNMPv3 if able.
            Severity: Medium Confidence: High

bandit/plugins/yaml_load.py

@@ -19,6 +19,8 @@
 
 :Example:
 
+.. code-block:: none
+
     >> Issue: [yaml_load] Use of unsafe yaml load. Allows instantiation of
        arbitrary objects. Consider yaml.safe_load().
        Severity: Medium   Confidence: High
@@ -28,7 +30,6 @@
     5 y = yaml.load(ystr)
     6 yaml.dump(y)
 
-
 .. seealso::
 
  - https://pyyaml.org/wiki/PyYAMLDocumentation#LoadingYAML