Update mixed.md

Author: expikr

test_book/src/individual/mixed.md

@@ -34,7 +34,7 @@ fn main(){
 Although markdown does not have a native figure caption syntax, one can use block quote as a general-purpose "environment" to emulate it, and max-level heading inside the quote as caption:
 
 > ![](https://rust-lang.org/logos/rust-logo-256x256-blk.png)
-> ###### Figure 1: Our belived logo in glorious 256x256 resolution
+> ###### Figure 1: Our beloved logo in glorious 256x256 resolution
 
 Since the heading is inside the block quote, it will not pollute the document heading structure.