message: Use consistent casing
diff: @@ -531,10 +531,10 @@ struct {
  Type declarations associate a name with a type:
  ```text
  -SID = u16;
  +Sid = u16;
  CharsetRange1 = struct {
  - first : SID,
  + first : Sid,
  nLeft : u8,
  };
  ```
  @@ -542,9 +542,9 @@ CharsetRange1 = struct {
  Type declarations can take arguments which are used in the definition of the type:
  ```text
  -Charset0(nGlyphs : u16) = struct {
  +Charset0(n_glyphs : u16) = struct {
  format : u8 == 0,
  - glyph : [SID; nGlyphs-1],
  + glyph : [Sid; n_glyphs - 1],
  };
  ```
  