Config's "ext" not being honored by the Rakefile

Changed "set :ext" to "markdown", so Textmate picks up on the formatting when opening files. But the task "new" still uses ".txt" after changing "config.ru" (toto itself is correctly using .markdown).

Inspect the Rakefile's "new" task and how it reads the "ext" setting from config.ru. Compare its behavior with toto, which already uses .markdown, then verify that running the "new" task honors the configured extension instead of always creating .txt files.

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