rust: move hgcli's README out of the way

My understanding is that it's not meant to be used in the current
form.

Differential Revision: https://phab.mercurial-scm.org/D7951

rust/README.rst

@@ -1,78 +1,19 b''
 ===================
 Mercurial Rust Code
 ===================
 
 This directory contains various Rust code for the Mercurial project.
 
 The top-level ``Cargo.toml`` file defines a workspace containing
 all primary Mercurial crates.
 
 Building
 ========
 
 To build the Rust components::
 
    $ cargo build
 
 If you prefer a non-debug / release configuration::
 
    $ cargo build --release
-
-Features
---------
-
-The following Cargo features are available:
-
-localdev (default)
-   Produce files that work with an in-source-tree build.
-
-   In this mode, the build finds and uses a ``python2.7`` binary from
-   ``PATH``. The ``hg`` binary assumes it runs from ``rust/target/<target>hg``
-   and it finds Mercurial files at ``dirname($0)/../../../``.
-
-Build Mechanism
----------------
-
-The produced ``hg`` binary is *bound* to a CPython installation. The
-binary links against and loads a CPython library that is discovered
-at build time (by a ``build.rs`` Cargo build script). The Python
-standard library defined by this CPython installation is also used.
-
-Finding the appropriate CPython installation to use is done by
-the ``python27-sys`` crate's ``build.rs``. Its search order is::
-
-1. ``PYTHON_SYS_EXECUTABLE`` environment variable.
-2. ``python`` executable on ``PATH``
-3. ``python2`` executable on ``PATH``
-4. ``python2.7`` executable on ``PATH``
-
-Additional verification of the found Python will be performed by our
-``build.rs`` to ensure it meets Mercurial's requirements.
-
-Details about the build-time configured Python are built into the
-produced ``hg`` binary. This means that a built ``hg`` binary is only
-suitable for a specific, well-defined role. These roles are controlled
-by Cargo features (see above).
-
-Running
-=======
-
-The ``hgcli`` crate produces an ``hg`` binary. You can run this binary
-via ``cargo run``::
-
-   $ cargo run --manifest-path hgcli/Cargo.toml
-
-Or directly::
-
-   $ target/debug/hg
-   $ target/release/hg
-
-You can also run the test harness with this binary::
-
-   $ ./run-tests.py --with-hg ../rust/target/debug/hg
-
-.. note::
-
-   Integration with the test harness is still preliminary. Remember to
-   ``cargo build`` after changes because the test harness doesn't yet
-   automatically build Rust code.

rust/hgcli/README.rst

@@ -1,78 +1,58 b''
-===================
-Mercurial Rust Code
-===================
-
-This directory contains various Rust code for the Mercurial project.
-
-The top-level ``Cargo.toml`` file defines a workspace containing
-all primary Mercurial crates.
-
-Building
-========
-
-To build the Rust components::
-
-   $ cargo build
-
-If you prefer a non-debug / release configuration::
-
-   $ cargo build --release
-
 Features
 --------
 
 The following Cargo features are available:
 
 localdev (default)
    Produce files that work with an in-source-tree build.
 
    In this mode, the build finds and uses a ``python2.7`` binary from
    ``PATH``. The ``hg`` binary assumes it runs from ``rust/target/<target>hg``
    and it finds Mercurial files at ``dirname($0)/../../../``.
 
 Build Mechanism
 ---------------
 
 The produced ``hg`` binary is *bound* to a CPython installation. The
 binary links against and loads a CPython library that is discovered
 at build time (by a ``build.rs`` Cargo build script). The Python
 standard library defined by this CPython installation is also used.
 
 Finding the appropriate CPython installation to use is done by
 the ``python27-sys`` crate's ``build.rs``. Its search order is::
 
 1. ``PYTHON_SYS_EXECUTABLE`` environment variable.
 2. ``python`` executable on ``PATH``
 3. ``python2`` executable on ``PATH``
 4. ``python2.7`` executable on ``PATH``
 
 Additional verification of the found Python will be performed by our
 ``build.rs`` to ensure it meets Mercurial's requirements.
 
 Details about the build-time configured Python are built into the
 produced ``hg`` binary. This means that a built ``hg`` binary is only
 suitable for a specific, well-defined role. These roles are controlled
 by Cargo features (see above).
 
 Running
 =======
 
 The ``hgcli`` crate produces an ``hg`` binary. You can run this binary
 via ``cargo run``::
 
    $ cargo run --manifest-path hgcli/Cargo.toml
 
 Or directly::
 
    $ target/debug/hg
    $ target/release/hg
 
 You can also run the test harness with this binary::
 
    $ ./run-tests.py --with-hg ../rust/target/debug/hg
 
 .. note::
 
    Integration with the test harness is still preliminary. Remember to
    ``cargo build`` after changes because the test harness doesn't yet
    automatically build Rust code.