[FIX] *: RST cleanup

RST cleanup to comply with the RST guidelines. This is required so we
can use "make test", as there are currently hundreds of errors. For now,
it is unusable because of the oldest code in this repo.

closes odoo/documentation#3581

Signed-off-by: Castillo Jonathan (jcs) <jcs@odoo.com>

content/applications/inventory_and_mrp/inventory/routes/concepts/cross_dock.rst

@@ -15,7 +15,7 @@ to reorganize products and load another truck.
    <https://www.odoo.com/blog/business-hacks-1/post/what-is-cross-docking-and-is-it-for-me-270>`_
 
 Configuration
-==============
+=============
 
 In the *Inventory* app, open :menuselection:`Configuration --> Settings` and activate the
 *Multi-Step Routes*.

content/applications/inventory_and_mrp/inventory/shipping/operation/labels.rst

@@ -81,8 +81,8 @@ Open the products you want to ship and set a weight on it.
     Don't forget to do the conversion if you are used to the imperial
     measurement system.
 
-How to print shipping labels ?
-===============================
+How to print shipping labels?
+=============================
 
 The delivery order created from the sale order will take the shipping
 information from it, but you can change the carrier if you want to.

content/applications/inventory_and_mrp/inventory/shipping/setup/sendcloud_shipping.rst

@@ -1,6 +1,6 @@
-============================================
+==========================================
 Set up Sendcloud shipping services in Odoo
-============================================
+==========================================
 
 Sendcloud is a shipping service aggregator that facilitates the integration of European
 shipping carriers with Odoo. Once integrated, users can select shipping carriers on inventory
@@ -11,7 +11,7 @@ operations in their Odoo database.
    /360059470491-Odoo-integration>`_
 
 Setup in Sendcloud
-===================
+==================
 
 Create an account and activate carriers
 ---------------------------------------