cmd: update help text

cmd/mkembedfs/help.txt

@@ -5,7 +5,7 @@ flags:
   -chdir <string>       change working directory before codegen
   -prefix <string>      path prefix for file keys, none by default
   -ignore <string>      path globs to ignore (allowed multiple times)
-  -module-name <string> generated module name, main by default
+  -module-name <string> generated module name, 'main' by default
-  -const-name <string>  generated constant name with data, embedfs by default
+  -const-name <string>  generated constant name with data, 'embedfs' by default
   -no-pub               do not make symbols in generated module public
-  -force-mimetype       set applicetion/octet-stream mime type for unknown files
+  -force-mimetype       set 'application/octet-stream' mime type for unknown files

cmd/mkembedfs/mkembedfs.v

@@ -38,8 +38,6 @@ fn main() {
 	println(generator.generate())
 }
 
-@[xdoc: 'generate code for embed directories with files into executable.']
-@[name: 'embedfs']
 struct FlagConfig {
 	help           bool
 	chdir          string

tests/mymod_test.out

@@ -1,6 +1,6 @@
 EmbedFileSystem{
     files: {'assets/example.json': EmbedFile{
-        data: embed_file.EmbedFileData{ len: 22, path: "assets/example.json", apath: "", uncompressed: 8462c4 }
+        data: embed_file.EmbedFileData{ len: 22, path: "assets/example.json", apath: "", uncompressed: 846284 }
         meta: EmbedFileMetadata{
             key: 'assets/example.json'
             name: 'example.json'