Fix remarks on __uacme_obtain.

type/__uacme_obtain/gencode-remote

@@ -19,5 +19,6 @@ then
 	confdir="$(cat "${__object:?}/parameter/confdir")"
 fi
 
-# Run renew script 'by hand' - renews will be handled by the cronjob.
+# Run renew script 'by hand' for intial issue - renews will be handled by the
+# cronjob.
 echo "$confdir/${__object_id:?}/renew.sh"

type/__uacme_obtain/man.rst

@@ -1,5 +1,5 @@
 cdist-type__uacme_obtain(7)
-========================
+===========================
 
 NAME
 ----
@@ -8,7 +8,7 @@ cdist-type__uacme_obtain - obtain, renew and deploy Let's Encrypt certificates
 DESCRIPTION
 -----------
 
-This type leverage uacme to issue abd renew Let's Encrypt certificates and
+This type leverage uacme to issue and renew Let's Encrypt certificates and
 provides a simple deployment mechanism. It is expected to be called after
 `__uacme_account`.
 
@@ -26,10 +26,10 @@ confdir
   uacme configuration directory.
 
 hookscript
-  Path to challenge hook program.
+  Path to the challenge hook program.
 
 owner
-  Owner of installed certificate (e.g. `www-data`), pass as argument to `chown`.
+  Owner of installed certificate (e.g. `www-data`), passed to `chown`.
 
 install-cert-to
   Installation path of the issued certificate.
@@ -44,7 +44,7 @@ force-cert-ownership-to
   Override default ownership for TLS certificate, passed as argument to chown.
 
 OPTIONAL MULTIPLE PARAMETERS
--------------------
+----------------------------
 altdomains
   Alternative domain names for this certificate.
 

type/__uacme_obtain/manifest

@@ -15,7 +15,7 @@ case "$os" in
 	;;
 esac
 
-CHALLENGEDIR=$default_challengedir
+CHALLENGEDIR=${default_challengedir:?}
 if [ -f "${__object:?}/parameter/challengedir" ];
 then
 	CHALLENGEDIR="$(cat "${__object:?}/parameter/challengedir")"