Merge bitcoin/bitcoin#18568: doc: Clarify developer notes about constant naming

05f9770c1fa64bd9730cd6e18ec333e0801c00d6 doc: Clarify developer notes about constant naming (Russell Yanofsky)

Pull request description:

  I'm pretty sure developer notes were intended to say constants should be upper case and variables should be lower case, but right now they are ambiguous about whether to write:

  ```c++
  extern const int SYMBOL;
  ```

  or:

  ```c++
  extern const int g_symbol;
  ```

  First convention above is better than the second convention because it tells you without having to look anything up that the value of `SYMBOL` won't change at runtime. Also I haven't seen other c++ projects using the second convention.

ACKs for top commit:
  MarcoFalke:
    cr ACK 05f9770c1fa64bd9730cd6e18ec333e0801c00d6
  practicalswift:
    ACK 05f9770c1fa64bd9730cd6e18ec333e0801c00d6
  jarolrod:
    ACK 05f9770c1fa64bd9730cd6e18ec333e0801c00d6 🥃

Tree-SHA512: 766d0e25d9db818d45df4ad6386987014f2053584cbced4b755ceef8bda6b7e2cfeb34eb8516423bd03b140faaf577614d5e3be2799f7eed0eb439187ab85323

0 files changed, 0 insertions, 0 deletions