Add PSMisleadingBacktick to PSSA settings file.

This is to keep the PSSA settings file in sync with the default rules enabled in PSES.  This helps the user know what the "defaults" are.

Author: rkeithhill

examples/PSScriptAnalyzerSettings.psd1

@@ -10,6 +10,7 @@
     # Analyze **only** the following rules. Use IncludeRules when you want
     # to invoke only a small subset of the defualt rules.
     IncludeRules = @('PSAvoidDefaultValueSwitchParameter',
+                     'PSMisleadingBacktick',
                      'PSMissingModuleManifestField',
                      'PSReservedCmdletChar',
                      'PSReservedParams',