Minor inconsistency in description of Warnings between warnings.html and exceptions.html

[jakkdl]

Documentation

I don't see any reason for these two pages to have slight differences in their wording, and should be made consistent to avoid any confusion.

https://docs.python.org/3/library/warnings.html#warning-categories

SyntaxWarning: Base category for warnings about dubious syntactic features.
RuntimeWarning: Base category for warnings about dubious runtime features.

https://docs.python.org/3/library/exceptions.html#SyntaxWarning

Base class for warnings about dubious syntax.

https://docs.python.org/3/library/exceptions.html#RuntimeWarning

Base class for warnings about dubious runtime behavior.

Looking at the other warning descriptions:

1. Warning description should probably be synced as well
2. UserWarning same
3. EncodingWarning is missing from https://docs.python.org/3/library/warnings.html#warning-categories
4. And the order the warnings are listed in differs

The rest are either identical or have substantial differences that look intentional. Though perhaps these should be automatically synced/generated from the same source