syntax: nanorc: paint arguments of 'include' and 'extendsyntax' specially

The path after 'include' is not a regex and does not need to be quoted;
when it's unquoted, colorize it specially, instead of leaving it red.

The syntax name after 'extendsyntax' should be brightgreen, like after
'syntax', but it's better that the subsequent commands have their own
special color.

syntax/nanorc.nanorc

@@ -9,20 +9,24 @@ color brightred ".*"
 # Color names
 color yellow "^[[:blank:]]*(i?color|set[[:blank:]]+((error|function|key|mini|number|prompt|scroller|selected|spotlight|status|stripe|title)color))[[:blank:]]+(bold,)?(italic,)?(((bright|light)?(white|black|red|blue|green|yellow|magenta|cyan))|normal|pink|purple|mauve|lagoon|mint|lime|peach|orange|latte|grey|gray|#[[:xdigit:]]{3})?(,(((light)?(white|black|red|blue|green|yellow|magenta|cyan))|normal|pink|purple|mauve|lagoon|mint|lime|peach|orange|latte|grey|gray|#[[:xdigit:]]{3}))?\>"
 
-# Keywords
+# The arguments of two special commands
+color bold,purple "^[[:blank:]]*include[[:blank:]][^"]*([[:blank:]]|$)"
+color lime "^[[:blank:]]*extendsyntax[[:blank:]]+[[:alpha:]]+[[:blank:]]+(i?color|header|magic|comment|formatter|linter|tabgives)[[:blank:]]+.*"
+
+# The arguments of commands
 color brightgreen "^[[:blank:]]*(set|unset)[[:blank:]]+(afterends|allow_insecure_backup|atblanks|autoindent|backup|boldtext|bookstyle|breaklonglines|casesensitive|constantshow|cutfromcursor|emptyline|historylog|indicator|jumpyscrolling|linenumbers|locking|magic|minibar|mouse|multibuffer|noconvert|nohelp|nonewlines|positionlog|preserve|quickblank|rawsequences|rebinddelete|regexp|saveonexit|showcursor|smarthome|softwrap|stateflags|tabstospaces|trimblanks|unix|wordbounds|zap|zero)\>"
 color brightgreen "^[[:blank:]]*set[[:blank:]]+(backupdir|brackets|errorcolor|functioncolor|keycolor|matchbrackets|minicolor|numbercolor|operatingdir|promptcolor|punct|quotestr|scrollercolor|selectedcolor|speller|spotlightcolor|statuscolor|stripecolor|titlecolor|whitespace|wordchars)[[:blank:]]+"
 color brightgreen "^[[:blank:]]*set[[:blank:]]+(fill[[:blank:]]+-?[[:digit:]]+|(guidestripe|tabsize)[[:blank:]]+[1-9][0-9]*)\>"
 color brightgreen "^[[:blank:]]*bind[[:blank:]]+((\^([A-Za-z]|[]/@\^_`-]|Space)|([Ss][Hh]-)?[Mm]-[A-Za-z]|[Mm]-([][!"#$%&'()*+,./0-9:;<=>?@\^_`{|}~-]|Space))|F([1-9]|1[0-9]|2[0-4])|Ins|Del)[[:blank:]]+([a-z]+|".*")[[:blank:]]+(main|help|search|replace(with)?|yesno|gotoline|writeout|insert|execute|browser|whereisfile|gotodir|spell|linter|all)\>"
 color brightgreen "^[[:blank:]]*unbind[[:blank:]]+((\^([A-Za-z]|[]/@\^_`-]|Space)|([Ss][Hh]-)?[Mm]-[A-Za-z]|[Mm]-([][!"#$%&'()*+,./0-9:;<=>?@\^_`{|}~-]|Space))|F([1-9]|1[0-9]|2[0-4])|Ins|Del)[[:blank:]]+(main|help|search|replace(with)?|yesno|gotoline|writeout|insert|execute|browser|whereisfile|gotodir|spell|linter|all)\>"
-color brightgreen "^[[:blank:]]*extendsyntax[[:blank:]]+[[:alpha:]]+[[:blank:]]+(i?color|header|magic|comment|formatter|linter|tabgives)[[:blank:]]+.*"
+color brightgreen "^[[:blank:]]*extendsyntax[[:blank:]]+[[:alpha:]]+[[:blank:]]+"
 color brightgreen "^[[:blank:]]*(syntax[[:blank:]]+[^[:space:]]+|(formatter|linter)[[:blank:]]+.+)"
-color green "^[[:blank:]]*((un)?(bind|set)|include|syntax|header|magic|comment|formatter|linter|tabgives|extendsyntax)\>"
 
 # Strings
 color brightmagenta "[[:blank:]](start=)?".+""
 
-# Color commands
+# Commands
+color green "^[[:blank:]]*((un)?(bind|set)|include|syntax|header|magic|comment|formatter|linter|tabgives|extendsyntax)\>"
 color magenta "^[[:blank:]]*i?color\>|[[:blank:]](start=|end=)"
 
 # Control codes