Devicebufferless (#708)

* runs one metal kernel

* conv2d works

* ops tests are passing

* const folding

* all ops work

* pre commit always passes

* torch works

* working still

* fix graph test

* tests passing

* image almost works

* image conv works

* most images

* fix custom

* fix assignment

* fix compile enet

* clean up comments

* fix realize return value

* include shapetracker in LB repr

* copy should make a copy

* reenable method cache

* fix lna

* dtypes in graph

* forward only for IMAGE=2

* simple realize

* getting close

* fixup new api, it's good except the kernel count

* back to 197 kernels

* tests should pass

* go to a real float

* no type_on_cpu

* fix the docs

* put shapetracker back in it's proper place

.pre-commit-config.yaml

@@ -1,6 +1,12 @@
 repos:
   - repo: local
     hooks:
+      - id: docs
+        name: docs
+        entry: python3 docs/abstractions.py
+        language: system
+        always_run: true
+        pass_filenames: false
       - id: flake8
         name: flake8
         entry: flake8 tinygrad/ --indent-size=2 --select=F,E112,E113,E203,E304,E502,E702,E703,E71,E72,E731,W191,W6 --statistics -j4