Amend theme to better match original sonokai

Changes based on the following references:
(1) https://www.sainnhe.dev/post/contributing-guide/#sonokai
(2) https://github.com/sainnhe/sonokai/blob/master/colors/sonokai.vim

* Make constants white (1)
* Make builtin variables purple (1)
* Make members orange (1)
* Make labels red (2)
* Make operators red (1)
* Make all punctuation grey (2)
* Make builtin functions and macros green (2)
* Make diff delta blue (2)
* Make cursor match bg4 (2)
* Make visible whitespace bg4 (2)

runtime/themes/sonokai.toml

@@ -6,24 +6,22 @@
 # License: MIT License
 
 "type" = "blue"
-"constant" = "purple"
+"constant" = "fg"
 "constant.numeric" = "purple"
 "constant.character.escape" = "orange"
 "string" = "yellow"
 "comment" = "grey"
 "variable" = "fg"
-"variable.builtin" = "orange"
+"variable.builtin" = "purple"
 "variable.parameter" = "fg"
-"variable.other.member" = "fg"
-"label" = "orange"
+"variable.other.member" = "orange"
+"label" = "red"
 "punctuation" = "grey"
-"punctuation.delimiter" = "grey"
-"punctuation.bracket" = "fg"
 "keyword" = "red"
-"operator" = "orange"
+"operator" = "red"
 "function" = "green"
-"function.builtin" = "blue"
-"function.macro" = "purple"
+"function.builtin" = "green"
+"function.macro" = "green"
 "tag" = "yellow"
 "namespace" = "blue"
 "attribute" = "purple"
@@ -47,12 +45,12 @@
 "markup.raw" = "green"
 
 "diff.plus" = "green"
-"diff.delta" = "orange"
+"diff.delta" = "blue"
 "diff.minus" = "red"
 
 "ui.background" = { bg = "bg0" }
 "ui.cursor" = { modifiers = ['reversed'] }
-"ui.cursor.match" = { fg = "orange", bg = "diff_yellow" }
+"ui.cursor.match" = { bg = "bg4" }
 "ui.cursor.insert" = { fg = "black", bg = "grey" }
 "ui.cursor.select" = { fg = "bg0", bg = "blue" }
 "ui.selection" = { bg = "bg4" }
@@ -68,7 +66,7 @@
 "ui.text.focus" = "green"
 "ui.menu" = { fg = "fg", bg = "bg2" }
 "ui.menu.selected" = { fg = "bg0", bg = "green" }
-"ui.virtual.whitespace" = { fg = "grey_dim" }
+"ui.virtual.whitespace" = "bg4" 
 "ui.virtual.ruler" = { bg = "grey_dim" }
 
 info = { fg = 'green', bg = 'bg2' }