chore: Significantly restructure folder layout

This moves the various projects from "type-based" folders (such as
"services" or "tools") into more appropriate semantic folders (such as
"nix", "ops" or "web").

Deprecated projects (nixcon-demo & gotest) which only existed for
testing/demonstration purposes have been removed.

(Note: *all* builds are broken with this commit)

web/tazblog/blog/Main.hs

@@ -0,0 +1,24 @@
+-- | Main module for the blog's web server
+module Main where
+
+import Control.Applicative ((<$>), (<*>))
+import Server (runBlog)
+import System.Environment (getEnv)
+
+data MainOptions
+  = MainOptions
+      { blogPort :: Int,
+        resourceDir :: String
+        }
+
+readOpts :: IO MainOptions
+readOpts =
+  MainOptions
+    <$> (fmap read $ getEnv "PORT")
+    <*> getEnv "RESOURCE_DIR"
+
+main :: IO ()
+main = do
+  opts <- readOpts
+  putStrLn ("tazblog starting on port " ++ (show $ blogPort opts))
+  runBlog (blogPort opts) (resourceDir opts)