docs: more links to xonshrc article (xonsh#5505)

After xonsh#5099 xonsh#5491 we need more links to xonshrc article in our docs. So
I've added them.

## For community
⬇️ **Please click the 👍 reaction instead of leaving a `+1` or 👍
comment**

---------

Co-authored-by: a <[email protected]>

docs/customization.rst

@@ -201,7 +201,7 @@ The problem might be:
 - Your locale is not set to utf-8, to check this you can set the content of the
  environment variable ``LC_TYPE``
 - Your locale is correctly set but **after** xonsh started. This is typically
- the case if you set your ``LC_TYPE`` inside your ``.xonshrc`` and xonsh is
+ the case if you set your ``LC_TYPE`` inside your `xonshrc <xonshrc.rst>`_ and xonsh is
  your default/login shell. To fix this you should see the documentation of your
  operating system to know how to correctly setup environment variables before
  the shell start (``~/.pam_environment`` for example)

docs/packages.rst

@@ -84,7 +84,7 @@ or highlight syntax or set process title, respectively.
 If it does not find ``prompt-toolkit`` package, it will
 use the Python ``readline`` module (which reads configuration file ``.inputrc`` in a manner compatible with ``GNU readline``).
 To ensure xonsh uses ``readline`` even if ``prompt-toolkit`` is installed, configure this in your
-``.xonshrc`` file:
+`xonshrc <xonshrc.rst>`_ (e.g. ``~/.xonshrc``) file:
 
 .. code-block:: xonshcon
 

docs/platform-issues.rst

@@ -267,7 +267,7 @@ typing and avoid the ambiguity altogether:
 
  >>> aliases['d'] = ['cmd', '/c', 'dir']
 
-You can add aliases to your ``~/.xonshrc`` to have it always
+You can add aliases to your `xonshrc <xonshrc.rst>`_ to have it always
 available when xonsh starts.
 
 

docs/tutorial_history_backend.rst

@@ -39,7 +39,7 @@ content above into it.
 
 Now we need to tell xonsh to use it as the history backend. To do this
 we need xonsh to be able to find our file and this ``CouchDBHistory`` class.
-Putting the following code into ``~/.xonshrc`` file can achieve this.
+Putting the following code into `xonshrc <xonshrc.rst>`_ file can achieve this.
 
 .. code-block:: none
 

docs/tutorial_xontrib.rst

@@ -104,12 +104,11 @@ create the layout for your xontrib package.
 
 Loading Xontribs
 ================
-Xontribs may be loaded in a few different ways: from the config file
-(e.g. ``~/.config/xonsh/rc.xsh``), dynamically at runtime with
-the ``xontrib`` command, or its Python API.
+Xontribs may be loaded in a few different ways: from the `xonshrc <xonshrc.rst>`_ file
+(e.g. ``~/.xonshrc``), dynamically at runtime with the ``xontrib`` command, or its Python API.
 
 Extensions are loaded via the ``xontrib load`` command.
-This command may be run from anywhere in a xonshrc file or at any point
+This command may be run from anywhere in a `xonshrc <xonshrc.rst>`_ file or at any point
 after xonsh has started up.
 
 .. code-block:: xonsh