added dev notes document, updated logging defaults

config

@@ -4,4 +4,4 @@
 # defaults for local development.
 
 # Can be 0 (off), 1 (error), 2 (warn), 3 (info), 4 (debug), 5 (trace)
-logging = 3
+logging = 2

development.markdown

@@ -0,0 +1,48 @@
+These are commands that will likely be useful during development.
+
+For doing compilation you can do:
+
+    stack repl --test unison-shared
+    stack repl --test unison-node
+
+to launch a REPL with access to the tests in either the `shared` or `node` project. From here, do `Main.main` to run the tests (or `import Unison.Test.Interpreter as I` and then `I.main` to run a specific test), and `:r` for rapid recompile.
+
+To build/run the node container:
+
+    stack build --flag unison-node:leveldb unison-node
+    stack exec container
+
+You can leave off the `--flag unison-node:leveldb` if you want, but it seems to be faster than the other backends.
+
+What if you want a profiled build? Do:
+
+    stack build --executable-profiling --library-profiling --ghc-options="-fprof-auto -rtsopts" --flag:leveldb unison-node
+
+Again you can leave off the flag. To run the container with profiling enabled, you do:
+
+    stack exec -- container +RTS -p
+
+That will generate a `container.prof` plain text file with profiling data. [More info on profiling](https://downloads.haskell.org/~ghc/latest/docs/html/users_guide/profiling.html).
+
+To submit Unison programs to the container, do something like:
+
+    curl -H "Content-Type: text/plain; charset=UTF-8" --data-binary @unison-src/searchengine.u http://localhost:8081/compute/dummynode909
+
+You can use any name you want in place of `dummynode909`.
+
+Lastly, for viewing the output of a Unison program, there's currently just one way - using the `Debug.watch` or `Debug.log` functions:
+
+    -- Prints out labeled first argument then returns the second arg
+    Debug.log : forall a b . Text -> b -> a -> a
+
+    -- Prints out labeled version of its argument before returning
+    Debug.watch : forall a . Text -> a -> a
+
+Here's an example use:
+
+    do Remote
+      Remote.transfer alice
+      result := ...
+      pure (Debug.watch "got result" result)
+
+If you think the runtime is busted and need to do debugging of message flows (hopefully never!), you can edit the file `$(HOME)/.unisonconfig` and add a single line like `logging = 3` (3 is 'info', 2 is 'warn', the default). This will generate lots of output for even simple programs though.