RFR: docs JDK-8220261: fix headings in java.base

[Mandy Chung]

I looked through the webrev and this looks fine to me.

Mandy

On 3/20/19 2:50 PM, Jonathan Gibbons wrote:
> Please review a medium-sized but conceptually simple patch to fix most 
> of the headings in the generated documentation for java.base, as 
> described in [1]. This does not address the headings in 
> java.util.concurrent which are reported separately, in JDK-8220248.
>
> The intent is to ensure that the headings in the generated pages are 
> well-structured, with no gaps, and correct implicit nesting. 
> Generally, the changes fall into three kinds:
>
>  * Headings in doc-comments for modules, packages and types start at <h2>
>  * Headings in doc comments for constructors, fields, methods and other
>    members start at <h4>
>  * Headings in package.html and doc-files/*.html start at <h1>
>
> The headings have been verified with the doccheck utility.
>
> We cannot re-enable doclint accessibility checking for java.base until 
> JDK-8220248 has also been fixed.
>
> -- Jon
>
> JBS: https://bugs.openjdk.java.net/browse/JDK-8220261
> Webrev: http://cr.openjdk.java.net/~jjg/8220261/webrev.00/index.html
>
> [1]: 
> https://mail.openjdk.java.net/pipermail/jdk-dev/2019-March/002671.html
>