add hincrby.md(en)

hustdb/doc/doc/en/api/hustdb/hustdb/hincrby.md

@@ -0,0 +1,47 @@
+## hincrby ##
+
+**Interface:** `/hustdb/hincrby`
+
+**Method:** `GET | POST`
+
+**Parameter:** 
+
+*  **tb** (Required)  
+*  **key** (Required)  
+*  **val** (Required, GET: val is argument or POST: val is body)  
+*  **ttl** (Optional, default: 0)
+*  **ver** (Optional, default: 0) 
+
+**Sample A:**
+
+    curl -i -X GET "http://localhost:8085/hustdb/hset?tb=test_table&key=test_key&val=7"
+
+**Result A1:**
+
+	HTTP/1.1 412 Precondition Failed //tb maybe not hash, reject hash request;or tb not exist
+	Version: 0
+	VerError: false
+
+**Result A2:**
+
+	HTTP/1.1 200 OK
+	Version: 1
+	VerError: false
+    Content-Length: 2
+	Content-Type: text/plain
+
+	16 //if original value of test_key is 9, 9 + 7 = 16
+
+**Sample B:**
+
+    curl -i -X GET "http://localhost:8085/hustdb/hset?tb=test_table&key=test_key&val=7&ver=2"
+
+**Result B1:**
+
+	HTTP/1.1 401 Unauthorized
+	Version: 1
+	VerError: true
+
+[Previous](../hustcache.md)
+
+[Home](../../../index.md)