Re: [Cin] Blend Algebra and Program icons

We can put these new variables in the chapter Developer's Section --> Configuaration Features: https://cinelerra-gg.org/download/CinelerraGG_Manual/Configuration_Features.... by adding them in the final part (“Some influential environment variables:”), accompanied by a description similar to: "Introduced with Blend Algebra and Blend program plugins; can be used globally in \CGG{} for new developments." Suggestions on other sections where to mention them and maybe improve their description?