Update the README (#130)

This PR updates the repo README.org with information about the new partial result workflows. I actually think the best place to document those workflows and endpoints is the OpenAPI spec, but our OpenAPI spec is rudimentary at this point and it's unofficial and we don't have a good setup for adding arbitrary explanations to it outside the Haskell code, so let's keep this information in the README now until we our OpenAPI specs are official.

* Convert fromheight param reference to minheight

* Add explanation about the partial search results

* Update README.org

* Update README.org

README.org

@@ -149,7 +149,7 @@ As a new block comes in, its chain number is printed as a single digit.
 ~server~ is just like ~listen~ but also runs an HTTP server that serves a
 few endpoints for doing common queries.
 
-**** endpoints
+**** Endpoints
 
 - ~/txs/recent~ gets a list of recent transactions
 - ~/txs/search?search=foo&limit=20&offset=40~ searches for transactions containing the string ~foo~
@@ -159,12 +159,31 @@ few endpoints for doing common queries.
 - ~/coins~ returns just the coins in circulation
 - ~/txs/account/<account-identifier>?token=<token-name>&chainid=<chainid>&fromheight=<blockheight>&limit=<some-limit>&offset=<some-offset>~
   returns account information given some ~account-identifier~, ~token~ and
-  ~chainid~. The optional parameter ~fromheight~ forces the results to only have
-  blockheights less than or equal to it. If ~token~ is omitted, the token ~coin~
+  ~chainid~. The optional parameter ~minheight~ forces the results to only have
+  blockheights larger than than or equal to it. If ~token~ is omitted, the token ~coin~
   is assumed. If ~chainid~ is omitted, all chains are searched.
 
 For more detailed information, see the API definition [[https://github.com/kadena-io/chainweb-api/blob/master/lib/ChainwebData/Api.hs#L24][here]].
 
+**** Note about partial search results
+
+All of ~chainweb-data~'s search endpoints (~/txs/{events,search,account}~) support a common workflow
+for efficiently retrieving the results of a given search in non-overlapping batches.
+
+A request to any one of these endpoints that match more rows than the number asked with the ~limit~
+query parameter will respond with a ~Chainweb-Next~ response header containing a token. That token
+can be used to call the same endpoint with the same query parameters plus the token passed in via
+the ~next~ query parameter in order to retreive the next batch of results.
+
+~chainweb-data~ supports a ~Chainweb-Execution-Strategy~ request header that can be used (probably by
+~chainweb-data~ operators by setting it in the API gateway) to enable
+an upper bound on the amount of time the server will spend for searching results. Normally, the
+search endpoints will produce the given ~limit~-many results if the search matches at least that many
+entries. However, if ~Chainweb-Execution-Strategy: Bounded~ is passed in, the response can contain
+less than ~limit~ rows even though there are potentially more matches, if those matches aren't found
+quickly enough. In such a case, the returned ~Chainweb-Next~ token will act as a cursor for the search,
+so it's possible to keep searching by making successive calls with subsequent ~Chainweb-Next~ tokens.
+
 *** fill
 
 ~fill~ fills in missing blocks. This command used to be called ~gaps~ but it has