[IMP] accounting/l10n_in: enhance india localization doc

This commit improves the Indian localization documentation by resizing
GST Return snapshots to remove empty space, enhancing readability,
especially on lower-resolution devices. Additionally, information about
GSTR-1 validations has been inserted.

task-4574916

closes odoo/documentation#12117

Signed-off-by: Harsh Trivedi (hatr) <hatr@odoo.com>

content/applications/finance/fiscal_localizations/india.rst

@@ -422,11 +422,31 @@ Return Period** if it does not exist. GST Return file-in is done in **three step
 Send GSTR-1
 ~~~~~~~~~~~
 
-#. The user can verify the :ref:`GSTR-1 <india/gstr-1_report>` report before uploading it to the
-   **GST portal** by clicking :guilabel:`GSTR-1 Report`;
+#. Click :guilabel:`GSTR-1 Report` to verify the :ref:`GSTR-1 <india/gstr-1_report>` report before
+   uploading it to the **GST portal**.
 
-#. The user can also get details to be submitted in **GSTR-1** in **Spreadsheet view** by clicking
-   on :guilabel:`Generate`;
+   .. image:: india/gst-gstr-1-verify.png
+      :alt: GSTR-1 verify
+
+   .. note::
+      The system performs basic validations to ensure compliance with the GST portal's requirements.
+      Possible issues include:
+
+      - **Incorrect Tax Application:** The tax type does not match the :guilabel:`Fiscal Position`
+        (:guilabel:`CGST/SGST` applied instead of :guilabel:`IGST` for interstate transactions, or
+        :guilabel:`IGST` applied instead of :guilabel:`CGST/SGST` for intrastate transactions).
+      - **Missing HSN Code:** No HSN Code is defined for the product.
+      - **Invalid HSN Code for Services:** The HSN Code for a service does not start with "99" or is
+        incorrect.
+      - **Non-compliant UQC:** The Unit Quantity Code (UQC) does not meet Indian GST standards.
+
+      If any validation fails, the system alerts users with a warning, highlighting the
+      discrepancies and providing a direct link to the affected lines.
+
+      .. image:: india/gst-gstr-1-validation.png
+         :alt: GSTR-1 validation warning
+
+#. Click :guilabel:`Generate` to view the report in **Spreadsheet view**.
 
    .. image:: india/gst-gstr-1-generate.png
       :alt: GSTR-1 generate
@@ -435,7 +455,7 @@ Send GSTR-1
       :alt: GSTR-1 Spreadsheet View
 
 #. If the **GSTR-1** report is correct, then click :guilabel:`Push to GSTN` to send it to the **GST
-   portal**. The status of the :guilabel:`GSTR-1` report changes to :guilabel:`Sending`;
+   portal**. The status of the :guilabel:`GSTR-1` report changes to :guilabel:`Sending`.
 
    .. image:: india/gst-gstr-1-sending.png
       :alt: GSTR-1 in the Sending Status
@@ -458,15 +478,12 @@ Send GSTR-1
         :alt: GSTR-1 Sent
 
    - If the state of the **GSTR-1** is :guilabel:`Error in Invoice`, invoices can be checked for
-     errors in the :guilabel:`Log Note`. Once issues have been resolved, the user can click
+     errors in the chatter. Once issues have been resolved, the user can click
      :guilabel:`Push to GSTN` to submit the file again on the **GST portal**.
 
      .. image:: india/gst-gstr-1-error.png
         :alt: GSTR-1 Error in Invoice
 
-   .. image:: india/gst-gstr-1-error-log.png
-      :alt: GSTR-1 Error in Invoice Log
-
 #. Click :guilabel:`Mark as Filed` after filing the **GSTR-1** report on the **GST portal**. The
    status of the report changes to :guilabel:`Filed` in **Odoo**.
 
@@ -502,15 +519,15 @@ the **GSTR-2B** report with your Odoo bills;
       .. image:: india/gst-gstr-2b-matched.png
          :alt: GSTR-2B Matched
 
-   - If the status is :guilabel:`Partially Matched`, you can make changes in bills by clicking
-     :guilabel:`View Reconciled Bills`. Once it is done, click :guilabel:`re-match`.
+   - If the status is :guilabel:`Partially Matched`, you can review and modify the bills by
+     clicking :guilabel:`View Reconciled Bills`. This will display categorized discrepancies, such
+     as bills missing in Odoo or GSTR-2. After making the necessary corrections, click
+     :guilabel:`re-match` to update the reconciliation and ensure accuracy before finalizing the
+     report.
 
       .. image:: india/gst-gstr-2b-partially.png
          :alt: GSTR-2B Partially Matched
 
-      .. image:: india/gst-gstr-2b-reconcile.png
-         :alt: GSTR-2B Reconciled Bills
-
 .. _india/gstr-3:
 
 GSTR-3 report
@@ -525,7 +542,7 @@ This return is auto-generated by extracting information from **GSTR-1** and **GS
 #. Once the **GSTR-3** report has been verified by the user and the tax amount on the **GST portal**
    has been paid. Once paid, the report can be **closed** by clicking :guilabel:`Closing Entry`;
 
-   .. image:: india/gst-gstr-3.png
+   .. image:: india/gst-gstr-3-not_filed.png
       :alt: GSTR-3
 
 #. In :guilabel:`Closing Entry`, add the tax amount paid on the **GST portal** using challan, and