some improvements in the description

exercises/093_hello_c.zig

@@ -36,11 +36,11 @@
 //
 // So that all this does not remain a dry theroy now, let's just start
 // and call a C function out of Zig.
-//
+
 // our well-known "import" for Zig
 const std = @import("std");
 
-// new the import for C
+// and here the new the import for C
 const c = @cImport({
     @cInclude("unistd.h");
 });
@@ -50,9 +50,9 @@ pub fn main() void {
     // In order to output a text that can be evaluated by the
     // Zig Builder, we need to write it to the Error output.
     // In Zig we do this with "std.debug.print" and in C we can
-    // specify the file descriptor i.e. 2 for error console.
+    // specify a file descriptor i.e. 2 for error console.
     //
-    // In  this case we use 'write' to output 17 chars,
+    // In  this exercise we use 'write' to output 17 chars,
     // but something is missing...
     const c_res = write(2, "Hello C from Zig!", 17);