Replace (frankly atrocious) html.nanorc I can't seem to find the true…

… origin of with a modified version of the file from scopatz's repository (https://github.com/scopatz/nanorc). Modifications include basic highlighting the contents of script and style tag blocks, specifying tidy (html-tidy) as a formatter, and applying the highlighting to mhtml files (which, though far from perfect, is a huge improvement).

.config/nano/README.md

@@ -8,7 +8,6 @@
 * csh.nanorc
 * css.nanorc
 * etc-hosts.nanorc
-* html.nanorc
 * inputrc.nanorc
 * java.nanorc
 * json.nanorc
@@ -35,6 +34,7 @@
 
 # Modified:
 * git.nanorc
+* html.nanorc
 * markdown.nanorc
 * nanohelp.nanorc
 * toml.nanorc
@@ -47,3 +47,4 @@
 * Update markdown syntax rules, taking inspiration from the rules provided with nano by default (/usr/share/nano/markdown.nanorc). Alternatively, just use the default.
 * Extensively review troff syntax and update man syntax rules (low priority). Alternatively, just use the default.
 * Deprecate various copied files for the builtin defaults
+* Incorporate highlighting of CSS property names and delimiting semicolons into the style attribute of html elements in html.nanorc

.config/nano/html.nanorc

@@ -1,19 +1,46 @@
-############## HTML example
-##
-syntax "html" "\.htm[l]?$"
-#
-#Assorted Brackets, separators, and functions
-color brightblue start="<" end=">"
-#color blue start="<style>" end="</style>"
-color brightblue "<script>|</script>|<div>|</div>|</a>|<select>|</select>|<style>|</style>"
-color brightblue "<h(1|2|3|4|5|6)>|</h(1|2|3|4|5|6)>"
-color brightblue start="<div" end=">"
-color brightblue start="<a " end=">"
-#color red " action | checked | class | contextmenu | dir | for | href | id | lang | method | name | onclick | rel | src | style | tabindex | title | type | value "
-#
-color brightred "(alt|bgcolor|height|href|label|longdesc|name|onclick|onfocus|onload|onmouseover|size|span|src|style|target|type|value|width)="
-color red "&[^;[[:space:]]]*;"
-color magenta ""[^"]*"|qq\|.*\|"
-#
-#Comment coloring is last
-color green start="<!--" end="-->"
+## HTML syntax highlighting rules for Nano
+
+syntax "HTML" "\.html?(.j2)?(.twig)?$" "\.mhtml$"
+magic "HTML document"
+comment "<!--|-->"
+formatter tidy -m -q
+
+## Tag content blocks
+color latte,lightblack start="<script[^>]*>" end="</script>"
+color orange,lightblack start="<style[^>]*>" end="</style>"
+
+## Emphasis tags
+color brightwhite start="<([biu]|em|strong)[^>]*>" end="</([biu]|em|strong)>"
+
+## Tags
+color cyan start="<" end=">"
+
+## Attributes
+color brightblue "[[:space:]](abbr|accept(-charset)?|accesskey|action|[av]?link|alt|archive|axis|background|(bg)?color|border)="
+color brightblue "[[:space:]](cell(padding|spacing)|char(off|set)?|checked|cite|class(id)?|compact|code(base|tag)?|cols(pan)?)="
+color brightblue "[[:space:]](content(editable)?|contextmenu|coords|data|datetime|declare|defer|dir|enctype)="
+color brightblue "[[:space:]](for|frame(border)?|headers|height|hidden|href(lang)?|hspace|http-equiv|id|ismap)="
+color brightblue "[[:space:]](label|lang|longdesc|margin(height|width)|maxlength|media|method|multiple)="
+color brightblue "[[:space:]](name|nohref|noresize|noshade|object|on(click|focus|load|mouseover|keypress)|profile|readonly|rel|rev)="
+color brightblue "[[:space:]](rows(pan)?|rules|scheme|scope|scrolling|shape|size|span|src|standby|start|style|summary|pattern)="
+color brightblue "[[:space:]](tabindex|target|text|title|type|usemap|v?align|value(type)?|vspace|width|xmlns|xml:space)="
+color brightblue "[[:space:]](required|disabled|selected)[[:space:]=>]"
+
+## Strings
+color yellow ""(\\.|[^"])*""
+
+## Named character references and entities
+color red "&#?[[:alnum:]]*;"
+
+## Template strings (not in the HTML spec, but very commonly used)
+color magenta "\{[^\}]*\}\}?"
+color brightgreen "[[:space:]]((end)?if|(end)?for|in|not|(end)?block)[[:space:]]"
+
+## Comments
+color green start="<!--" end="-->"
+
+## Trailing spaces
+color ,green "[[:space:]]+$"
+
+## Reminders
+color brightwhite,yellow "(FIXME|TODO|XXX)"