document mxc2http better

.config/zsh/completions/_mxc2http

@@ -1,6 +1,7 @@
 #compdef mxc2http
 
 _arguments '-h[short help text]' \
+           '--help[short help text]' \
            '--server[server to use as host]:server:' \
            '*:url:_urls'
 

.config/zsh/functions/mxc2http

@@ -1,15 +1,16 @@
 #!/usr/bin/env zsh
 # Converts mxc:// URLs into https:// URLs
+# <https://spec.matrix.org/v1.2/client-server-api/#get_matrixmediav3downloadservernamemediaid>
 
 setopt LOCAL_OPTIONS ERR_RETURN NO_UNSET PIPE_FAIL
 
 zmodload zsh/zutil
 local -a o_help=()
 local -a o_server=()
-zparseopts -D -K -- h=o_help -server:=o_server
+zparseopts -D -K -- h=o_help -help=o_help -server:=o_server
 if [[ ${#o_help} -ne 0 || ! -v 1 ]]; then
     local ret=$(( ${#o_help} ^ 1 ))
-    print -u $(( 1 + ${ret} )) "usage: ${0} [-h] <URL> …"
+    print -u $(( 1 + ${ret} )) "usage: ${0} [-h|--help] [--server HOST] <URL> …"
     return ${ret}
 fi
 local -a urls=(${@})