Add serialization 101

website/docs/usage/_spacy-101/_serialization.jade

@@ -0,0 +1,35 @@
+//- 💫 DOCS > USAGE > SPACY 101 > SERIALIZATION
+
+p
+    |  If you've been modifying the pipeline, vocabulary vectors and entities, or made
+    |  updates to the model, you'll eventually want
+    |  to #[strong save your progress] – for example, everything that's in your #[code nlp]
+    |  object. This means you'll have to translate its contents and structure
+    |  into a format that can be saved, like a file or a byte string. This
+    |  process is called serialization. spaCy comes with
+    |  #[strong built-in serialization methods] and supports the
+    |  #[+a("http://www.diveintopython3.net/serializing.html#dump") Pickle protocol].
+
++aside("What's pickle?")
+    |  Pickle is Python's built-in object persistance system. It lets you
+    |  transfer arbitrary Python objects between processes. This is usually used
+    |  to load an object to and from disk, but it's also used for distributed
+    |  computing, e.g. with
+    |  #[+a("https://spark.apache.org/docs/0.9.0/python-programming-guide.html") PySpark]
+    |  or #[+a("http://dask.pydata.org/en/latest/") Dask]. When you unpickle an
+    |  object, you're agreeing to execute whatever code it contains. It's like
+    |  calling #[code eval()] on a string – so don't unpickle objects from
+    |  untrusted sources.
+
+p
+    |  All container classes and pipeline components, i.e.
+    for cls in ["Doc", "Language", "Tokenizer", "Tagger", "DependencyParser", "EntityRecognizer", "Vocab", "StringStore"]
+        |  #[+api(cls.toLowerCase()) #[code=cls]],
+    |  have the following methods available:
+
++table(["Method", "Returns", "Example"])
+    - style = [1, 0, 1]
+    +annotation-row(["to_bytes", "bytes", "nlp.to_bytes()"], style)
+    +annotation-row(["from_bytes", "object", "nlp.from_bytes(bytes)"], style)
+    +annotation-row(["to_disk", "-", "nlp.to_disk('/path')"], style)
+    +annotation-row(["from_disk", "object", "nlp.from_disk('/path')"], style)

website/docs/usage/saving-loading.jade

@@ -1,5 +1,15 @@
 include ../../_includes/_mixins
 
++h(2, "101") Serialization 101
+
+include _spacy-101/_serialization
+
++infobox("Important note")
+    |  In spaCy v2.0, the API for saving and loading has changed to only use the
+    |  four methods listed above consistently across objects and classes. For an
+    |  overview of the changes, see #[+a("/docs/usage/v2#incompat") this table]
+    |  and the notes on #[+a("/docs/usage/v2#migrating-saving-loading") migrating].
+
 
 +h(2, "models") Saving models
 

website/docs/usage/spacy-101.jade

@@ -105,6 +105,10 @@ include _spacy-101/_word-vectors
 
 +h(2, "pipelines") Pipelines
 
++h(2, "serialization") Serialization
+
+include _spacy-101/_serialization
+
 +h(2, "architecture") Architecture
 
 +image