Update specification

Author: kdheepak

doc/panvimdoc.md

@@ -268,7 +268,7 @@ You can even use `<details>` and `<summary>` tags for your README.md.
 
 <details>
 
-<summary>Summary</summary>
+<summary><b>Summary</b></summary>
 
 This section is the details.
 
@@ -277,7 +277,7 @@ This section is the details.
 The `html` tags are dropped and the following output is generated in the vimdoc file.
 
 ```
-Summary
+Summary ~
 
 This section is the details.
 ```

scripts/panvimdoc.lua

@@ -261,8 +261,10 @@ end
 
 function RawInline(format, str)
   if format == "html" then
-    if str == "<b>" or str == "</b>" then
-      return "**"
+    if str == "<b>" then
+      return ""
+    elseif str == "</b>" then
+      return " ~"
     elseif str == "<i>" or str == "</i>" then
       return "_"
     else