Update CodeQL Style guide to mention acronyms

Adding this after asking how to do this internally. Is based on https://dart.dev/guides/language/effective-dart/style#do-capitalize-acronyms-and-abbreviations-longer-than-two-letters-like-words

docs/ql-style-guide.md

@@ -173,6 +173,7 @@ private predicate foo(Expr e, Expr p) {
 1. Use [camelCase](https://en.wikipedia.org/wiki/Camel_case) for:
    - Predicate names
    - Variable names
+1. Abbreviations and acronyms *should* use normal PascalCase/camelCase (if there are only two letters, it is generally ok to use all uppercase letters).
 1. Newtype predicate names *should* begin with `T`.
 1. Predicates that have a result *should* be named `get...`
 1. Predicates that can return multiple results *should* be named `getA...` or `getAn...`
@@ -183,6 +184,7 @@ private predicate foo(Expr e, Expr p) {
 1. Use names as they are used in the target-language specification.
 1. Use American English.
 
+
 ### Examples
 
 ```ql
@@ -209,6 +211,9 @@ class Type extends ... {
 
   /** ... */
   Type getATypeParameter() { ... }
+  
+  /** ... */
+  predicate getHttpConnection() { ... }
 }
 ```