fixed mount tutorial, as mentioned on tuwel https://tuwel.tuwien.ac.a…

…t/mod/forum/discuss.php?d=243029#p598964 and issue ElektraInitiative#3722, also added sudo to the first command, which is necessary anyway

doc/tutorials/mount.md

@@ -158,7 +158,7 @@ So let us have a look at the [type](/src/plugins/type/README.md) and [mathcheck]
 
 ```sh
 # mount the backend with the plugins ...
-kdb mount example.ni user:/example ni type
+sudo kdb mount example.ni user:/example ni type
 
 # ... and set a value for the demonstration
 kdb set user:/example/enumtest/fruit apple
@@ -169,11 +169,11 @@ By entering `kdb plugin-info type` in the commandline, we can find out how to us
 It turns out that this plugin allows us to define a list of valid values for our keys via the metavalue `check/enum`.
 
 ```sh
-kdb meta-set user:/example/enumtest/fruit check/type enum
 kdb meta-set user:/example/enumtest/fruit check/enum "#2"
 kdb meta-set user:/example/enumtest/fruit check/enum/#0 apple
 kdb meta-set user:/example/enumtest/fruit check/enum/#1 banana
 kdb meta-set user:/example/enumtest/fruit check/enum/#2 grape
+kdb meta-set user:/example/enumtest/fruit check/type enum
 kdb set user:/example/enumtest/fruit tomato
 # RET:5
 # this fails because tomato is not in the list of valid values