[1.16.5] Screen rendering methods deprecated

Hi,

I started porting my mod to 1.16.5 (getting zero downloads of the newest version was a strong indicator it's time to move on) and I noticed that many of the RenderSystem methods are deprecated. For example:

          RenderSystem.color4f(float, float, float, float);
          RenderSystem.pushMatrix();
          RenderSystem.popMatrix();

After some research, I found that the new way of doing things is batch rendering. However, I can't find any good examples or tutorials on what methods I should use.

So my question would be: is there any documentation or summary on the topic and does this change also affect other things like, for example, entity rendering?