Add section explaining possible breadcrumb levels

src/includes/set-level/javascript.mdx

@@ -4,6 +4,8 @@ To set the level out of scope, you can call `captureMessage()` per event:
 Sentry.captureMessage("this is a debug message", "debug");
 ```
 
+Available levels are `"fatal"`, `"critical"`, `"error"`, `"warning"`, `"log"`, `"info"`, and `"debug"`.
+
 To set the level within scope, you can call `setLevel()`:
 
 ```javascript

src/platforms/common/enriching-events/breadcrumbs.mdx

@@ -41,6 +41,12 @@ The available breadcrumb keys are `type`, `category`, `message`, `level`, `times
 
 </PlatformSection>
 
+<PlatformSection supported={["javascript", "node"]}>
+
+You can choose from the following breadcrumb log levels: `"fatal"`, `"critical"`, `"error"`, `"warning"`, `"log"`, `"info"`, and `"debug"`.
+
+</PlatformSection>
+
 <PlatformSection notSupported={["native", "unreal"]}>
 
 ## Automatic Breadcrumbs

src/platforms/javascript/common/troubleshooting/index.mdx

@@ -395,12 +395,12 @@ document.body.addEventListener(
     if (event.target.tagName === "IMG") {
       Sentry.captureMessage(
         `Failed to load image: ${event.target.src}`,
-        "warning" // message severity level
+        "warning"
       );
     } else if (event.target.tagName === "LINK") {
       Sentry.captureMessage(
         `Failed to load css: ${event.target.href}`,
-        "warning" // message severity level
+        "warning"
       );
     }
   },