fix .jpg not being detected (#458)

* Fix .jpg not being detected properly (Fix #455)

* Fix compiler errors

rest/src/main/kotlin/Image.kt

@@ -1,10 +1,10 @@
 package dev.kord.rest
 
-import io.ktor.client.HttpClient
-import io.ktor.client.request.request
-import io.ktor.client.statement.HttpResponse
-import io.ktor.http.HttpMethod
-import io.ktor.util.toByteArray
+import io.ktor.client.*
+import io.ktor.client.request.*
+import io.ktor.client.statement.*
+import io.ktor.http.*
+import io.ktor.util.*
 import kotlinx.coroutines.Dispatchers
 import java.util.*
 
@@ -14,7 +14,7 @@ class Image private constructor(val data: ByteArray, val format: Format) {
     val dataUri: String
         get() {
             val hash = Base64.getEncoder().encodeToString(data)
-            return "data:image/${format.extension};base64,$hash"
+            return "data:image/${format.extensions.first()};base64,$hash"
         }
 
     companion object {
@@ -34,23 +34,31 @@ class Image private constructor(val data: ByteArray, val format: Format) {
         }
     }
 
-    sealed class Format(val extension: String) {
-        object JPEG : Format("jpeg")
+    sealed class Format(val extensions: List<String>) {
+        constructor(vararg extensions: String) : this(extensions.toList())
+
+        val extension: String get() = extensions.first()
+
+        object JPEG : Format("jpeg", "jpg")
         object PNG : Format("png")
         object WEBP : Format("webp")
         object GIF : Format("gif")
 
         companion object {
-            val values: Set<Format> get() = setOf(
-                JPEG,
-                PNG ,
-                WEBP,
-                GIF ,
+            val values: Set<Format>
+                get() = setOf(
+                    JPEG,
+                    PNG,
+                    WEBP,
+                    GIF,
+                )
 
-            )
             fun isSupported(fileName: String): Boolean {
-                return values.any { fileName.endsWith(it.extension, true) }
+                return values.any {
+                    it.extensions.any { extension -> fileName.endsWith(extension, true) }
+                }
             }
+
             fun fromContentType(type: String) = when (type) {
                 "image/jpeg" -> JPEG
                 "image/png" -> PNG