changeset 2872:78debdfb3e4d

doc: simplify the reference to in-core features

This should do the whole thing lighter.

--- a/docs/index.rst	Tue Aug 29 16:14:28 2017 +0200
+++ b/docs/index.rst	Tue Aug 29 16:15:02 2017 +0200
@@ -20,33 +20,21 @@
 commit new changesets to modify your source code, but you cannot
 modify or remove old changesets.
 
-For years, Mercurial has included various extensions that allow
-history modification: ``rebase``, ``mq``, ``histedit``, and so forth.
-These are useful and popular extensions, and in fact history
-modification is one of the big reasons DVCSes (distributed version
-control systems) like Mercurial took off.
-
+For years, Mercurial has included various commands that allow
+history modification: ``rebase``, ``histedit``, ``commit --amend`` and so forth.
 But there's a catch: until now, Mercurial's various mechanisms for
 modifying history have been *unsafe*, in that changesets were
 destroyed (“stripped”) rather than simply made hidden.
 
-``evolve`` makes things better in a couple of ways:
+``evolve`` makes things better by changing the behaviour of most existing
+history modification commands so they use a safer mechanism (*changeset
+obsolescence*, covered below) rather than the older, less safe *strip*
+operation.
 
-  * It changes the behaviour of most existing history modification
-    extensions (``rebase``, ``histedit``, etc.) so they use a safer
-    mechanism (*changeset obsolescence*, covered below) rather than
-    the older, less safe *strip* operation.
-
-  * It provides a new way of modifying history that is roughly
-    equivalent to ``mq`` (but much nicer and safer).
-
-It helps to understand that ``evolve`` builds on infrastructure
-already in core Mercurial:
+``evolve`` is built on infrastructure in core Mercurial:
 
   * *Phases* (starting in Mercurial 2.1) allow you to distinguish
-    mutable and immutable changesets. We'll cover phases early in the
-    user guide, since understanding phases is essential to
-    understanding ``evolve``.
+    mutable and immutable changesets.
 
   * *Changeset obsolescence* (starting in Mercurial 2.3) is how
     Mercurial knows how history has been modified, specifically when
@@ -54,8 +42,7 @@
     changeset is neither removed nor modified, but is instead marked
     *obsolete* and typically replaced by a *successor*. Obsolete
     changesets usually become *hidden* as well. Obsolescence is an
-    invisible feature until you start using ``evolve``, so we'll cover
-    it in the user guide too.
+    invisible feature in Mercurial until you start using ``evolve``.
 
 Some of the things you can do with ``evolve`` are: