app/write: major refactor+rewrite

+ Make synosaurus unconditional
+ Move much of +write-mode into its hook
+ Conform README.org to template and expand it
+ Try to guess langtool-language-tool-jar
+ Update init.example.el entry
+ Remove redundant variables
+ Add +write-text-scale & +text-line-spacing variables

init.example.el

@@ -134,7 +134,9 @@
       ;irc               ; how neckbeards socialize
       ;rss               ; emacs as an RSS reader
       ;twitter           ; twitter client https://twitter.com/vnought
-       ;; (write +synosaurus +wordnut +langtool)             ; emacs as a word processor (latex + org + markdown)
+      ;(write            ; emacs as a word processor (latex + org + markdown)
+      ; +wordnut         ; wordnet (wn) search
+      ; +langtool)       ; a proofreader (grammar/style check) for Emacs
 
        ;; Private modules are where you place your personal configuration files.
        ;; By default, they are not tracked. There is one module included here,