Update version.h.in header comments

Currently, the comments in the version.h.in header file are
incorrect. This tiny patch just updates them.

Author: baylesj

src/lib_json/version.h.in

@@ -1,5 +1,5 @@
-// DO NOT EDIT. This file (and "version") is generated by CMake.
-// Run CMake configure step to update it.
+// DO NOT EDIT. This file (and "version") is a template used by the build system
+// (either CMake or Meson) to generate a "version.h" header file.
 #ifndef JSON_VERSION_H_INCLUDED
 #define JSON_VERSION_H_INCLUDED
 
@@ -8,7 +8,9 @@
 #define JSONCPP_VERSION_MINOR @JSONCPP_VERSION_MINOR@
 #define JSONCPP_VERSION_PATCH @JSONCPP_VERSION_PATCH@
 #define JSONCPP_VERSION_QUALIFIER
-#define JSONCPP_VERSION_HEXA ((JSONCPP_VERSION_MAJOR << 24) | (JSONCPP_VERSION_MINOR << 16) | (JSONCPP_VERSION_PATCH << 8))
+#define JSONCPP_VERSION_HEXA ((JSONCPP_VERSION_MAJOR << 24) \
+                            | (JSONCPP_VERSION_MINOR << 16) \
+                            | (JSONCPP_VERSION_PATCH << 8))
 
 #ifdef JSONCPP_USING_SECURE_MEMORY
 #undef JSONCPP_USING_SECURE_MEMORY