Further documentation improvements

README.md

@@ -19,6 +19,10 @@ improving this infrastructure.
   Make sure `pdflatex` and `latexmk` are installed on your system
   already.
 
+  You'll need Python3 and the items in `requirements.txt`.  You can
+  install the latter with `pip3 install -r requirements.txt` or use your
+  usual python dependency management system.
+
 * Set up the **`OTS_DOCTOOLS_DIR`** environment variable.
 
   Set the environment variable OTS_DOCTOOLS_DIR to point to the
@@ -50,7 +54,10 @@ already be the case.  Just run
 
       $ make foo.pdf
 
-to build `foo.pdf` from `foo.ltx`.  For draft PDFs, use `make foo.draft.pdf`.
+to build `foo.pdf` from `foo.ltx`.  For draft PDFs, use `make
+foo.draft.pdf`.  (Note that you can also do this by setting the
+`draft` variable to `true` at the top of the document, as discussed in
+[Latex + Jinja Usage](#latex-jinja-usage) below.)
 
 ## Pipeline and Plugins
 
@@ -96,15 +103,20 @@ input file:
   ---
 ```
 
-Certain variables will be treated specially.  For example, the values
-of `title` and `date` will be displayed on the title page.  (Remember,
-backslashes are doubled here because they need to be quoted for
-jinja.)  If the value of `draft` is `true`, then every page will get a
-large, light gray "DRAFT" diagonal watermark.
+Certain variables will be treated specially:
+
+* The values of `title` and `date` will be displayed on the title
+  page.  (Remember, backslashes are doubled here because they need to
+  be quoted for jinja.)
+
+* If the value of `draft` is `true`, then every page will get a large,
+  light gray "DRAFT" diagonal watermark.  (Note that you can also
+  cause this to happen by building `foo.draft.pdf` instead `foo.pdf`,
+  as documented earlier in [Building Documents](#building-documents).)
 
-Other variables are just there to be referred to later.  For example,
-in the above example, the value of `fruit` is `durian`, so if you put
-this in your latex:
+Other variables are just there to be referred to later.  In the above
+example, the value of `fruit` is `durian`, so if you put this in your
+LaTeX:
 
 ```
   I always ate eggplant, even when offered \VAR{fruit}.
@@ -155,9 +167,3 @@ Linux and OS X should generally do the right thing with these
 materials.  We have not documented how to set this up on Windows
 because we haven't tried that setup.  If you're on Windows, please let
 us know how it goes and how we can improve these materials.
-
-## Dependencies
-
-You'll need Python3 and the items in `requirements.txt`.  You can
-install the latter with `pip3 install -r requirements.txt` or use your
-usual python dependency management system.