Clarify some of the language

book/CH00_Introduction.adoc

@@ -135,7 +135,7 @@ grown up knowing nothing but Single Page Applications and the frameworks that ar
 In particular, many young web developers began their careers by building React.js applications that interact with a Node server using a
 JSON API; they may never have learned about hypermedia as a system at all.
 
-This is a tragedy, and, frankly, a failure on the part of the thought leaders in the web development community to properly
+This is a tragedy, and, frankly, a failure on the part of the web development community to properly
 communicate and advocate for the hypermedia approach.
 
 Hypermedia was a great idea!  It still is!

book/CH01_HypermediaAReintroduction.adoc

@@ -543,7 +543,7 @@ was describing in his dissertation.
 These applications tend to be clunky, but they work reasonably well.  Many web developers and teams choose to accept the
 limitations of plain HTML in the interest of simplicity and reliability.
 
-Rich Harris, creator of Svelte.js, a popular SPA library, and a thought-leader on the SPA side of the debate, has proposed a mix
+Rich Harris, creator of Svelte.js, a popular SPA library, and an advocate on the SPA side of the debate, has proposed a mix
 of this older MPA style and the newer SPA style.  Harris calls this approach to building web applications "`transitional,`" in that
 it attempts to blend the MPA approach and the newer SPA approach into a coherent whole.  (This is somewhat
 similar to the "`transitional`" trend in architecture, which combines traditional and modern architectural styles.)