Fix: broken internal links for jekyll build, header missing id

Added the missing id tag to link the documentation to the HTML file generated by jekyll on build

Author: heyolaniran

library-structure.adoc

@@ -9,6 +9,10 @@ The internally-used libraries generally have unstable APIs making them unsuitabl
 
 Bitcoin Core has a https://github.com/bitcoin/bitcoin/blob/master/doc/design/libraries.md[guide^] which describes the various libraries, their conventions, and their various dependencies.
 
+[id=library-dependency-graph]
+.Bitcoin library dependency graph
+[mermaid, target=bitcoion-lib-dependencies]
+
 ```mermaid
 
 %%{ init : { "flowchart" : { "curve" : "basis" }}}%%