Update Postgress Changes documentation page

[ilkovulchev]

Hello,

I had a problem with receiving real time updates on larger table columns. The community helped me out and told me what the issue is, long story short, due to the TOAST technique that Postgress uses, the replica identity had to be changed to full and that worked.

I was then showed, also, that this is mentioned in the documentation in the Postgress Changes page under the Receiving old records page and indeed it was, sort of, not fully.
However I do not think that this is the best way and place to provide this information. It's not very relatable to the actual problem and why its happening, which is why I could not find it to begin with (but then again, I also could have looked more thoroughly).

I think this information should be mentioned in point 6 of the Quick start section "Listen to changes by schema", since it would be relevant there. Something along the lines of UPDATE *see potential limitations to the payload/record, or something of that nature, which will then, if clicked, take you to a section on the page where a short explanation about the TOAST technique along with the solution (changing the replica identity) is written.

Thank you.