docs: adding skeleton README.md files for all vlib modules (#13034)

vlib/dl/README.md

@@ -0,0 +1,6 @@
+## Description:
+
+`dl` can be used to Dynamically Load a library during runtime.
+It is a thin wrapper over `LoadLibrary` on Windows, and `dlopen` on Unix.
+
+Using it, you can implement a plugin system for your application.

vlib/dl/dl.v

@@ -1,9 +1,8 @@
 module dl
 
-pub const (
-	version = 1
-	dl_ext  = get_shared_library_extension()
-)
+pub const version = 1
+
+pub const dl_ext = get_shared_library_extension()
 
 // get_shared_library_extension returns the platform dependent shared library extension
 // i.e. .dll on windows, .so on most unixes, .dylib on macos.

vlib/dl/dl_nix.c.v

@@ -6,10 +6,9 @@ $if linux {
 	#flag -ldl
 }
 
-pub const (
-	rtld_now  = C.RTLD_NOW
-	rtld_lazy = C.RTLD_LAZY
-)
+pub const rtld_now = C.RTLD_NOW
+
+pub const rtld_lazy = C.RTLD_LAZY
 
 fn C.dlopen(filename &char, flags int) voidptr
 

vlib/dl/dl_windows.c.v

@@ -1,9 +1,8 @@
 module dl
 
-pub const (
-	rtld_now  = 0
-	rtld_lazy = 0
-)
+pub const rtld_now = 0
+
+pub const rtld_lazy = 0
 
 fn C.LoadLibrary(libfilename &u16) voidptr