Add new fields to mem input readme

plugins/inputs/mem/README.md

@@ -14,22 +14,45 @@ For a more complete explanation of the difference between *used* and
 
 ### Metrics:
 
+Available fields are dependent on platform.
+
 - mem
   - fields:
-  	- active (int)
-  	- available (int)
-  	- buffered (int)
-  	- cached (int)
-  	- free (int)
-  	- inactive (int)
-  	- slab (int)
-  	- total (int)
-  	- used (int)
+    - active (integer)
+    - available (integer)
+    - buffered (integer)
+    - cached (integer)
+    - free (integer)
+    - inactive (integer)
+    - slab (integer)
+    - total (integer)
+    - used (integer)
     - available_percent (float)
     - used_percent (float)
-  	- wired (int)
+    - wired (integer)
+    - commit_limit (integer)
+    - committed_as (integer)
+    - dirty (integer)
+    - high_free (integer)
+    - high_total (integer)
+    - huge_page_size (integer)
+    - huge_pages_free (integer)
+    - huge_pages_total (integer)
+    - low_free (integer)
+    - low_total (integer)
+    - mapped (integer)
+    - page_tables (integer)
+    - shared (integer)
+    - swap_cached (integer)
+    - swap_free (integer)
+    - swap_total (integer)
+    - vmalloc_chunk (integer)
+    - vmalloc_total (integer)
+    - vmalloc_used (integer)
+    - write_back (integer)
+    - write_back_tmp (integer)
 
 ### Example Output:
 ```
-mem cached=7809495040i,inactive=6348988416i,total=20855394304i,available=11378946048i,buffered=927199232i,active=11292905472i,slab=1351340032i,used_percent=45.43883523785713,available_percent=54.56116476214287,used=9476448256i,free=1715331072i 1511894782000000000
+mem active=11347566592i,available=18705133568i,available_percent=89.4288960571006,buffered=1976709120i,cached=13975572480i,commit_limit=14753067008i,committed_as=2872422400i,dirty=87461888i,free=1352400896i,high_free=0i,high_total=0i,huge_page_size=2097152i,huge_pages_free=0i,huge_pages_total=0i,inactive=6201593856i,low_free=0i,low_total=0i,mapped=310427648i,page_tables=14397440i,shared=200781824i,slab=1937526784i,swap_cached=0i,swap_free=4294963200i,swap_total=4294963200i,total=20916207616i,used=3611525120i,used_percent=17.26663449848977,vmalloc_chunk=0i,vmalloc_total=35184372087808i,vmalloc_used=0i,wired=0i,write_back=0i,write_back_tmp=0i 1536704085000000000
 ```