Adding docs, specs and fixing object returned

docs/api/structures/memory-info.md

@@ -0,0 +1,12 @@
+# MemoryInfo Object
+
+* `workingSetSize` Integer - Process id of the process.
+* `workingSetSize` Integer - The amount of memory currently pinned to actual physical RAM.
+* `peakWorkingSetSize` Integer - The maximum amount of memory that has ever been pinned
+  to actual physical RAM.
+* `privateBytes` Integer - The amount of memory not shared by other processes, such as
+  JS heap or HTML content.
+* `sharedBytes` Integer - The amount of memory shared between processes, typically
+  memory consumed by the Electron code itself
+
+Note that all statistics are reported in Kilobytes.

docs/api/structures/process-memory-info.md

@@ -0,0 +1,4 @@
+# ProcessMemoryInfo Object
+
+* `pid` Integer - Process id of the process.
+* `memory` MemoryInfo - Memory information of the process.