tweaks

adding some of the correct terms and references, depreciation

packages/mermaid/src/docs/syntax/gantt.md

@@ -472,20 +472,27 @@ gantt
 ```
 
 
-### Timeline (with comments, CSS, settings, and Obsidian-style preprocessor)
+### Timeline (with comments, CSS, config in frontmatter, directives)
 
 ```mermaid-example
 ---
-    # triple line MUST be first. yaml comment.
+    # triple line MUST be first to start frontmatter. Then, any consistent indent
+    # yaml style comment
     displayMode: compact
+    config:
+#        theme: forest
+#        themeCSS: " #item36 { fill: CadetBlue } "
+        gantt:
+            useWidth: 400
+
 ---
 %%{
     init: { 
-        'themeCSS': ' #item36 { fill: CadetBlue } ', 
-        'Comment': 'Not official, but common in JSON',
-        'themeCSS': ' rect[id^=workaround] { height: calc(100% - 50px) ; transform: translate(9px, 25px); y: 0; width: 1.5px; stroke: none; fill: red; } text[id^=workaround] { fill: red; y: 100%; font-size: 15px;}',
+        'Comment': 'Not official, but common JSON style comment',
+        'Comment': 'Depreciated 2023 for frontmatter, easier to format, overrides frontmatter',
+        'themeCSS': ' #item36 { fill: CadetBlue }    rect[id^=workaround] { height: calc(100% - 50px) ; transform: translate(9px, 25px); y: 0; width: 1.5px; stroke: none; fill: red; } text[id^=workaround] { fill: red; y: 100%; font-size: 15px;}',
         'gantt':{  
-            'useWidth': 400, 'rightPadding': 0
+            'usedWidth': 400, 'rightPadding': 0
         }
     } 
 }%%
@@ -500,13 +507,13 @@ gantt
     section Issue19062
     71   :            item71, 1900, 1930
     section Issue19401
-    36   :            item36, 1913, 1935
+    36   :            item36, 1913, 1935 %% themeCSS targets #item36 as id directly 
     section Issue1300
     94   :            item94, 1910, 1915
     5    :            item5,  1920, 1925
     0    : milestone, item0,  1918, 1s
     9    : vert,              1906, 1s %% not yet official
-    64   : workaround,        1923, 1s %% custom CSS object https://github.com/mermaid-js/mermaid/issues/3250
+    64   : workaround,        1923, 1s %% custom CSS object in themeCSS https://github.com/mermaid-js/mermaid/issues/3250
 ```