Regex patterns automod rule trigger (bwmarrin#1275)

* feat: add regex pattern automod trigger

Add regex patterns metadata to AutoModerationTriggerMetadata.

* feat: add regex pattern example

Add showcase of regex filter into auto_moderation example.

* feat: cosmetic changes

Add period to the end of RegexPatterns documentation comment.

examples/auto_moderation/main.go

@@ -32,6 +32,7 @@ func main() {
 		TriggerType: discordgo.AutoModerationEventTriggerKeyword,
 		TriggerMetadata: &discordgo.AutoModerationTriggerMetadata{
 			KeywordFilter: []string{"*cat*"},
+			RegexPatterns: []string{"(c|b)at"},
 		},
 
 		Enabled: &enabled,

structs.go

@@ -1427,6 +1427,10 @@ type AutoModerationTriggerMetadata struct {
 	// Substrings which will be searched for in content.
 	// NOTE: should be only used with keyword trigger type.
 	KeywordFilter []string `json:"keyword_filter,omitempty"`
+	// Regular expression patterns which will be matched against content (maximum of 10).
+	// NOTE: should be only used with keyword trigger type.
+	RegexPatterns []string `json:"regex_patterns,omitempty"`
+
 	// Internally pre-defined wordsets which will be searched for in content.
 	// NOTE: should be only used with keyword preset trigger type.
 	Presets []AutoModerationKeywordPreset `json:"presets,omitempty"`