Support for custom URL roots about odd-jobs

[saurabhnanda]

@ivanbakel I believe the code already supports this. Please take a look at the following function -

odd-jobs/src/OddJobs/Endpoints.hs

Lines 77 to 83 in ab15d8b

	mkEnv :: (MonadIO m) => Config -> (Text -> Text) -> m Env
	mkEnv cfg@Config{..} linksFn = do
	allJobTypes <- fetchAllJobTypes cfg
	allJobRunners <- fetchAllJobRunners cfg
	envJobTypesRef <- newIORef allJobTypes
	envJobRunnersRef <- newIORef allJobRunners
	let envRoutes = routes linksFn

The second argument is a function that allows you to transform the links generated by the web UI to whatever you want. This "hook" was added specifically for your use-case.

Are you starting the web UI via the default command-line? We can probably add another flag --web-ui-root-path to make this easier without having to write custom code.

[ivanbakel]

Good to know, thanks! I am using the default command-line settings to start the web UI, so a flag would be really useful. I'll make a PR to support doing that.

[saurabhnanda]

@ivanbakel before you work on the PR, please take a look at #76 -- this might make your PR easier.