Start typing anywhere and change featured images with clear buttons

We cleaned up a few spots in the post editor where it wasn't clear where to click to start typing or how to change the featured image.

• Click empty space to start typing: Clicking the empty area below your content places the cursor at the end of the post, or on the first line of a new post. If the post ends with an image or embed, you can start a new paragraph after it, and clicking the left or right margin moves the cursor to the line at that height.
• Separate buttons on the featured image: Hover over the featured image to see the buttons that fit its current state. An automatically generated OG image offers Upload Image and Open OG image editor, and an image you uploaded offers Replace image and Delete image. On touch devices the buttons are always visible, and you can also drop a file onto the image to upload it. The recommended size is 1200 x 630 px.
• Know why a share link can't be created: External share links in post Preview are available on the Team plan or during the free trial. Blogs without access now see a message explaining this instead of the link field closing with no message, and the blog dashboard also shows a View plans button. If creating a link fails, you'll see an error and the name you entered stays in place.

If you also have an image made with the OG image editor, your uploaded image takes priority. Delete the uploaded image later and the OG editor image is used again.