With the new browser extension, WhoKnows lets you import skills from any web page including your web profiles like LinkedIn, Quora, StackExchange, etc as well as any online documents or contents you may have written. Here's how.
Navigate to your profile or content that you wrote.
Click the WhoKnows button in your toolbar.
You'll see the list of skills that were found on that page like below and either add all of them or click to individually add the skills you want published to your profile.