Docs: Replace outdated link in README

[aimurphy]

The "error handling done right" blog no longer exists.

I have suggested replacements within the DataStax drivers developer guide. The server error page, in particular, links to several other pages that address specific error handling concepts (like retry policies). These pages, by extension, link to the specific Java driver docs for those subjects.

The Java driver documentation will need to be republished so this change is propagated over there as well.

[aimurphy]

@absurdfarce / @SiyaoIsHiding - If you could please help me get this merged to replace a dead link in the README?

[SiyaoIsHiding]

Thank you very much! Looks good to me!

[SiyaoIsHiding]

cc @lukasz-antoniak too

[absurdfarce]

Hmmmm, the content we're pointing to now looks to be a catalog of known error conditions (driver-side and server-side) which is quite different from the content that used to be there. I think I'd rather just remove this section entirely. The argument for putting this in the top-level README was that awareness of the concepts discussed in that article could be useful for developers... I'm not sure that's as true for the current content.

[aimurphy]

@absurdfarce that's fine too. Would you like me to make that change?

[absurdfarce]

I think that would be my preference @aimurphy ... actually just remove the "Error Handling" section all together.

[absurdfarce]

I think this is the most straightforward approach to handle the removed content