const.adoc does not reference to #define properly

[SeppPenner]

https://github.com/arduino/reference-en/edit/master/Language/Variables/Variable%20Scope%20&%20Qualifiers/const.adoc

#define is only referenced correctly once.

[robsoncouto]

#434 was not accepted because there were enough mentions to the #define page already

[SeppPenner]

@robsoncouto In my opinion it would make sense to reference all occurences of these. But I will open a discussion in the issues.

[SeppPenner]

I have created an issue for a general discussion on this. In my opinion it would make sense to link every occurence of functions or constants. #462