partial bitcoin#30454: Introduce CMake-based build system

includes:
- 6ce50fd (only some changes to `depends/README.md`)

Author: kwvg

depends/README.md

@@ -92,9 +92,13 @@ For linux S390X cross compilation:
 
     pkg install bash
 
+### Install the required dependencies: NetBSD
+
+    pkgin install bash gmake
+
 ### Install the required dependencies: OpenBSD
 
-    pkg_add bash gtar
+    pkg_add bash gmake gtar
 
 ### Dependency Options