Update SA1305 doc to mention allowedHungarianPrefixes in stylecop.json

Author: Youssef1313

documentation/SA1305.md

@@ -29,9 +29,17 @@ In addition, modern code editors such as Visual Studio make it easy to identify
 
 StyleCop assumes that any variable name that begins with one or two lower-case letters followed by an upper-case letter is making use of Hungarian notation, and will flag a violation of this rule in each case. It is possible to declare certain prefixes as legal, in which case they will be ignored. For example, a variable named *onExecute* will appear to StyleCop to be using Hungarian notation, when in reality it is not. Thus, the *on* prefix should be flagged as an allowed prefix.
 
-To configure the list of allowed prefixes, bring up the StyleCop settings for a project, and navigate to the Hungarian tab, as shown below:
-
-![](Images/HungarianSettings.JPG)
+To configure the list of allowed prefixes, use *stylecop.json* like the following:
+
+```json
+{
+  "settings": {
+    "namingRules": {
+      "allowedHungarianPrefixes": [ "aa", "bb" ],
+    },
+  }
+}
+```
 
 Adding a one or two letter prefix to this list will cause StyleCop to ignore variables or fields which begin with this prefix.