Note usable methods in examples

This change also rewrites all example lead-ins to come *before* the examples, and not after.

README.md

@@ -60,23 +60,25 @@ Seaweed-FS uses HTTP REST operations to write, read, delete. The return results
 ```
 
 ### Write File ###
-Here is a simple usage on how to save a file:
+
+To upload a file, first, send a HTTP POST, PUT, or GET request to `/dir/assign` to get an fid and a volume server url:
 
 ```
 > curl -X POST http://localhost:9333/dir/assign
 {"count":1,"fid":"3,01637037d6","url":"127.0.0.1:8080","publicUrl":"localhost:8080"}
 ```
-First, send a HTTP request to get an fid and a volume server url.
+
+Second, to store the file content, send a HTTP multipart PUT or POST request to `url + '/' + fid` from the response:
 
 ```
 > curl -X PUT -F file=@/home/chris/myphoto.jpg http://127.0.0.1:8080/3,01637037d6
 {"size": 43234}
 ```
-Second, send a HTTP multipart POST request to the volume server url+'/'+fid, to really store the file content.
 
-For update, send another POST request with updated file content. 
+For update, send another PUT or POST request with updated file content. 
+
+For deletion, send an HTTP DELETE request to the same `url + '/' + fid` URL:
 
-For deletion, send a http DELETE request
 ```
 > curl -X DELETE http://127.0.0.1:8080/3,01637037d6
 ```
@@ -94,20 +96,28 @@ If stored as a string, in theory, you would need 8+1+16+8=33 bytes. A char(33) w
 If space is really a concern, you can store the file id in your own format. You would need one 4-byte integer for volume id, 8-byte long number for file key, 4-byte integer for file cookie. So 16 bytes are enough (more than enough).
 
 ### Read File ###
+
 Here is the example on how to render the URL.
+
+First lookup the volume server's URLs by the file's volumeId:
+
 ```
 > curl http://localhost:9333/dir/lookup?volumeId=3
 {"locations":[{"publicUrl":"localhost:8080","url":"localhost:8080"}]}
 ```
-First lookup the volume server's URLs by the file's volumeId. However, since usually there are not too many volume servers, and volumes does not move often, you can cache the results most of the time. Depends on the replication type, one volume can have multiple replica locations. Just randomly pick one location to read.
+
+(However, since usually there are not too many volume servers, and volumes does not move often, you can cache the results most of the time. Depends on the replication type, one volume can have multiple replica locations. Just randomly pick one location to read.)
 
 Now you can take the public url, render the url or directly read from the volume server via url:
+
 ```
  http://localhost:8080/3,01637037d6.jpg
 ```
+
 Notice we add an file extension ".jpg" here. It's optional and just one way for the client to specify the file content type.
 
 If you want a nicer URL, you can use one of these alternative URL formats:
+
 ```
  http://localhost:8080/3/01637037d6/my_preferred_name.jpg
  http://localhost:8080/3/01637037d6.jpg
@@ -118,11 +128,13 @@ If you want a nicer URL, you can use one of these alternative URL formats:
 
 ### Rack-Aware and Data Center-Aware Replication ###
 Seaweed-FS apply the replication strategy on a volume level. So when you are getting a file id, you can specify the replication strategy. For example:
+
 ```
 curl -X POST http://localhost:9333/dir/assign?replication=001
 ```
 
-Here is the meaning of the replication parameter 
+Here is the meaning of the replication parameter:
+
 ```
 000: no replication
 001: replicate once on the same rack
@@ -138,14 +150,18 @@ https://code.google.com/p/weed-fs/wiki/RackDataCenterAwareReplication
 You can also set the default replication strategy when starting the master server.
 
 ### Allocate File Key on specific data center ###
-Volume servers can start with a specific data center name.
+
+Volume servers can start with a specific data center name:
+
 ```
  weed volume -dir=/tmp/1 -port=8080 -dataCenter=dc1
  weed volume -dir=/tmp/2 -port=8081 -dataCenter=dc2
 ```
+
 Or the master server can determine the data center via volume server's IP address and settings in weed.conf file.
 
-Now when requesting a file key, an optional "dataCenter" parameter can limit the assigned volume to the specific data center. For example, this specify
+Now when requesting a file key, an optional "dataCenter" parameter can limit the assigned volume to the specific data center. For example, this specifies that the assigned volume should be limited to 'dc1':
+
 ```
  http://localhost:9333/dir/assign?dataCenter=dc1
 ```