add full support of parse mode in captions

- parse_mode of caption support in AudioConfig
 - parse_mode of caption support in DocumentConfig
 - parse_mode of caption support in VideoConfig
 - parse_mode of caption support in VoiceConfig
 - in PhotoConfig add parse_mode only if caption is not empty

configs.go

@@ -253,10 +253,10 @@ func (config PhotoConfig) params() (map[string]string, error) {
 
 	if config.Caption != "" {
 		params["caption"] = config.Caption
-	}
 		if config.ParseMode != "" {
 			params["parse_mode"] = config.ParseMode
 		}
+	}
 
 	return params, nil
 }
@@ -271,10 +271,11 @@ func (config PhotoConfig) values() (url.Values, error) {
 	v.Add(config.name(), config.FileID)
 	if config.Caption != "" {
 		v.Add("caption", config.Caption)
-	}
 		if config.ParseMode != "" {
 			v.Add("parse_mode", config.ParseMode)
 		}
+	}
+
 	return v, nil
 }
 
@@ -292,6 +293,7 @@ func (config PhotoConfig) method() string {
 type AudioConfig struct {
 	BaseFile
 	Caption   string
+	ParseMode string
 	Duration  int
 	Performer string
 	Title     string
@@ -317,6 +319,9 @@ func (config AudioConfig) values() (url.Values, error) {
 	}
 	if config.Caption != "" {
 		v.Add("caption", config.Caption)
+		if config.ParseMode != "" {
+			v.Add("parse_mode", config.ParseMode)
+		}
 	}
 
 	return v, nil
@@ -338,6 +343,9 @@ func (config AudioConfig) params() (map[string]string, error) {
 	}
 	if config.Caption != "" {
 		params["caption"] = config.Caption
+		if config.ParseMode != "" {
+			params["parse_mode"] = config.ParseMode
+		}
 	}
 
 	return params, nil
@@ -357,6 +365,7 @@ func (config AudioConfig) method() string {
 type DocumentConfig struct {
 	BaseFile
 	Caption   string
+	ParseMode string
 }
 
 // values returns a url.Values representation of DocumentConfig.
@@ -369,6 +378,9 @@ func (config DocumentConfig) values() (url.Values, error) {
 	v.Add(config.name(), config.FileID)
 	if config.Caption != "" {
 		v.Add("caption", config.Caption)
+		if config.ParseMode != "" {
+			v.Add("parse_mode", config.ParseMode)
+		}
 	}
 
 	return v, nil
@@ -380,6 +392,9 @@ func (config DocumentConfig) params() (map[string]string, error) {
 
 	if config.Caption != "" {
 		params["caption"] = config.Caption
+		if config.ParseMode != "" {
+			params["parse_mode"] = config.ParseMode
+		}
 	}
 
 	return params, nil
@@ -434,6 +449,7 @@ type VideoConfig struct {
 	BaseFile
 	Duration  int
 	Caption   string
+	ParseMode string
 }
 
 // values returns a url.Values representation of VideoConfig.
@@ -449,6 +465,9 @@ func (config VideoConfig) values() (url.Values, error) {
 	}
 	if config.Caption != "" {
 		v.Add("caption", config.Caption)
+		if config.ParseMode != "" {
+			v.Add("parse_mode", config.ParseMode)
+		}
 	}
 
 	return v, nil
@@ -460,6 +479,9 @@ func (config VideoConfig) params() (map[string]string, error) {
 
 	if config.Caption != "" {
 		params["caption"] = config.Caption
+		if config.ParseMode != "" {
+			params["parse_mode"] = config.ParseMode
+		}
 	}
 
 	return params, nil
@@ -530,6 +552,7 @@ func (config VideoNoteConfig) method() string {
 type VoiceConfig struct {
 	BaseFile
 	Caption   string
+	ParseMode string
 	Duration  int
 }
 
@@ -546,6 +569,9 @@ func (config VoiceConfig) values() (url.Values, error) {
 	}
 	if config.Caption != "" {
 		v.Add("caption", config.Caption)
+		if config.ParseMode != "" {
+			v.Add("parse_mode", config.ParseMode)
+		}
 	}
 
 	return v, nil
@@ -560,6 +586,9 @@ func (config VoiceConfig) params() (map[string]string, error) {
 	}
 	if config.Caption != "" {
 		params["caption"] = config.Caption
+		if config.ParseMode != "" {
+			params["parse_mode"] = config.ParseMode
+		}
 	}
 
 	return params, nil