added comments and haltonerror=false

Signed-off-by: Pratik Mankawde <3397372+pratikmankawde@users.noreply.github.com>

include/xrpl/shamap/SHAMapNodeID.h

@@ -47,6 +47,17 @@ public:
         return id_;
     }
 
+    /**
+     * Get the SHAMapNodeID of a child node at the specified branch.
+     *
+     * @param m  The branch number (0-15) indicating which child to descend to.
+     *           In the SHAMap's 16-way radix tree, each inner node has up to
+     *           16 children, indexed by the corresponding nibble (4 bits) of
+     *           the key at the current depth.
+     * @return SHAMapNodeID of the child node at branch m.
+     * @throws std::logic_error if this node is at the maximum leaf depth (64)
+     *         or if the node's id doesn't match its depth mask.
+     */
     SHAMapNodeID
     getChildNodeID(unsigned int m) const;