[GH-19267] Spelling comments (#19268)

* spelling: comments

Signed-off-by: Josh Soref <jsoref@users.noreply.github.com>
Co-authored-by: Josh Soref <jsoref@users.noreply.github.com>
Co-authored-by: Mattermod <mattermod@users.noreply.github.com>

model/post_metadata.go

@@ -14,7 +14,7 @@ type PostMetadata struct {
 	// Files holds information about the file attachments on the post.
 	Files []*FileInfo `json:"files,omitempty"`
 
-	// Images holds the dimensions of all external images in the post as a map of the image URL to its diemsnions.
+	// Images holds the dimensions of all external images in the post as a map of the image URL to its dimensions.
 	// This includes image embeds (when the message contains a plaintext link to an image), Markdown images, images
 	// contained in the OpenGraph metadata, and images contained in message attachments. It does not contain
 	// the dimensions of any file attachments as those are stored in FileInfos.