docs: change heading level for 'icons' section (modelcontextprotocol#1914)

* fix(docs): change heading level for 'icons' section

Updated heading level for 'icons' section in documentation.

* fix(docs): change heading level for 'icons' section

Author: kpman

docs/specification/2025-11-25/basic/index.mdx

@@ -216,7 +216,7 @@ may reserve particular names for purpose-specific metadata, as declared in those
 - Unless empty, MUST begin and end with an alphanumeric character (`[a-z0-9A-Z]`).
 - MAY contain hyphens (`-`), underscores (`_`), dots (`.`), and alphanumerics in between.
 
-#### `icons`
+### `icons`
 
 The `icons` property provides a standardized way for servers to expose visual identifiers for their resources, tools, prompts, and implementations. Icons enhance user interfaces by providing visual context and improving the discoverability of available functionality.
 

docs/specification/draft/basic/index.mdx

@@ -216,7 +216,7 @@ may reserve particular names for purpose-specific metadata, as declared in those
 - Unless empty, MUST begin and end with an alphanumeric character (`[a-z0-9A-Z]`).
 - MAY contain hyphens (`-`), underscores (`_`), dots (`.`), and alphanumerics in between.
 
-#### `icons`
+### `icons`
 
 The `icons` property provides a standardized way for servers to expose visual identifiers for their resources, tools, prompts, and implementations. Icons enhance user interfaces by providing visual context and improving the discoverability of available functionality.