docs(api): update ordering for $eval and $$eval

[arjunattam]

...to be consistent with how we order $ and $$ - the inconsistency has been bothering me. However, this fails on doc lint. I could update the linter along with this.

DocLint Failures:
  1) [MarkDown] Bad alphabetic ordering of Page members: Page.$eval() should go after Page.$$eval()
  2) [MarkDown] Bad alphabetic ordering of Frame members: Frame.$eval() should go after Frame.$$eval()
  3) [MarkDown] Bad alphabetic ordering of ElementHandle members: ElementHandle.$eval() should go after ElementHandle.$$eval()

[dgozman]

I am fine with this, please go ahead and update the liner.

[arjunattam]

I learnt something new about JS strings. $ < $$, but $eval > $$eval. I've updated doclint to replace multiple occurrences of $ with one.