Fix typos in XEB documentation and notebooks

[mhucka]

Cross-Entropy Benchmarking should be hyphenated; also, for consistency, it should be either always capitalized or never. Since more places in the docs capitalize it, this commit changes all of them to follow suit.

[codecov]

Codecov Report

All modified and coverable lines are covered by tests ✅

Project coverage is 98.64%. Comparing base (8c8a21a) to head (1a1f45c).
Report is 4 commits behind head on main.

Additional details and impacted files

@@           Coverage Diff           @@
##             main    #7254   +/-   ##
=======================================
  Coverage   98.64%   98.64%           
=======================================
  Files        1106     1106           
  Lines       95990    95990           
=======================================
+ Hits        94691    94692    +1     
+ Misses       1299     1298    -1     

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[pavoljuhas]

LGTM. Can you please tuck in an extra one-character fix?

(On mac pbpaste | git apply should work after copying the patch)

diff --git a/docs/transform/custom_transformers.ipynb b/docs/transform/custom_transformers.ipynb
index ab4962f8..e64f4258 100644
--- a/docs/transform/custom_transformers.ipynb
+++ b/docs/transform/custom_transformers.ipynb
@@ -167,3 +167,3 @@
     "### `cirq.TransformerLogger` and support for automated logging\n",
-    "The `cirq.TransformerLogger` class is used to log the actions of a transformer on an input circuit. `@cirq.transformer` decorator automatically adds support for logging the initial and final circuits for each transfomer step. "
+    "The `cirq.TransformerLogger` class is used to log the actions of a transformer on an input circuit. `@cirq.transformer` decorator automatically adds support for logging the initial and final circuits for each transformer step. "
    ]
diff --git a/docs/transform/routing_transformer.ipynb b/docs/transform/routing_transformer.ipynb
index 8f1c5723..415df0ef 100644
--- a/docs/transform/routing_transformer.ipynb
+++ b/docs/transform/routing_transformer.ipynb
@@ -98,3 +98,3 @@
    "source": [
-    "## Routing as a `@cirq.transfomer`"
+    "## Routing as a `@cirq.transformer`"
    ]