Added vmem arena file

Going to need to roll my own for my use case.

code/grime_vmem_arena.odin

@@ -0,0 +1,10 @@
+/*
+Odin's virtual arena allocator doesn't do what I ideally want for allocation resizing or growing from a large vmem reserve.
+
+So this is a simple virtual memory backed arena allocator designed
+to take advantage of one large contigous reserve of memory.
+With the expectation that resizes with its interface will only occur using the last allocated block.
+*/
+package sectr
+
+