improve tutorial titles

scribblings/tutorial-first.scrbl

@@ -2,7 +2,7 @@
 
 @(require (for-label pollen/world racket) "mb-tools.rkt")
 
-@title[#:tag "first-tutorial"]{First tutorial}
+@title[#:tag "first-tutorial"]{First tutorial: the project server & preprocessor}
 
 In this tutorial, you'll use Pollen to make a single HTML page with a poem. You'll learn about:
 

scribblings/tutorial-fourth.scrbl

@@ -7,7 +7,7 @@
 @(my-eval `(require pollen pollen/decode pollen/template pollen/tag xml racket/list txexpr))
 
 
-@title[#:tag "fourth-tutorial"]{Fourth tutorial}
+@title[#:tag "fourth-tutorial"]{Fourth tutorial: multiple output targets}
 
 In previous tutorial projects, we've maintained a one-to-one relationship between source files and output files. In this tutorial, however, you'll learn how to generate output in multiple formats from a single Pollen source file. You'll learn about:
 

scribblings/tutorial-second.scrbl

@@ -4,7 +4,7 @@
 
 @(require "mb-tools.rkt")
 
-@title[#:tag "second-tutorial"]{Second tutorial}
+@title[#:tag "second-tutorial"]{Second tutorial: Markdown, templates, & pagetrees}
 
 In this tutorial, you'll use Pollen to publish a multiple-page article written in Markdown. You'll learn about:
 

scribblings/tutorial-third.scrbl

@@ -7,7 +7,7 @@
 @(my-eval `(require pollen pollen/decode pollen/template pollen/tag xml racket/list txexpr))
 
 
-@title[#:tag "third-tutorial"]{Third tutorial}
+@title[#:tag "third-tutorial"]{Third tutorial: Pollen markup & tag functions}
 
 Now you're getting to the good stuff. In this tutorial, you'll use Pollen to publish a multi-page article written in Pollen markup. You'll learn about: