init import tracking plan docs

Author: forstisabella

src/protocols/tracking-plan/create.md

@@ -42,6 +42,8 @@ To download a Tracking Plan:
 4. Open the Download History page by clicking the link in the toast or clicking the **Download History** tab in the top navigation bar.
 5. Once the file status column indicates that the download was successful, click the link in the File column to download your CSV to your computer. If the file status column shows the download has failed, return to the Tracking Plan Overview page or the Tracking Plan page and try the download again.<br/> The Tracking Plan CSV name has the following format:<br/>`workspaceSlug-trackingPlanName--yyyy-mm-dd--hh-mm-utc`
 
+Once you've downloaded a Tracking Plan, you can use it as a template to make changes to the Tracking Plan, which you can then [upload back to your Tracking Plan](#) to directly apply your changes. 
+
 ## Delete a Tracking Plan
 
 > info "Deleting a Tracking Plan requires Workspace Owner or Tracking Plan Admin permissions"
@@ -87,6 +89,34 @@ You can define which traits you expect to see passed in Identify or Group calls
 
 It's best to keep traits optional because Identify and Group are often called and pass only _new or changed_ traits, because Segment's client-side libraries (analytics.js, Swift, Kotlin) cache traits in local storage. See the [Identify Best Practices](/docs/connections/spec/best-practices-identify#when-and-how-often-to-call-identify) to learn more.
 
+### Upload a Tracking Plan
+
+You can make changes to a Tracking Plan by directly uploading a new Tracking Plan CSV to your existing Tracking Plan. Segment provides a template you can use, or you can [download your Tracking Plan](#download-a-tracking-plan) and make changes directly to that CSV file. 
+
+> info "Tracking Plans with imported libraries cannot be changed using the Upload a Tracking Plan method"
+> If you have a Tracking Plan with imported libraries, you must make changes directly to your Tracking Plan.
+
+To update a Tracking Plan using a CSV file: 
+1. Click **Protocols** in the left navigation bar. 
+2. On the row of the Tracking Plan you want to edit, open the contextual menu(...) and select **View Tracking Plan**.
+3. Select **Edit Tracking Plan**.
+4. Click the **Import...** button and select **From CSV**. 
+5. Download the Tracking Plan template CSV and fill in the template CSV file with your new Tracking Plan rules, or make changes to your [downloaded Tracking Plan](#download-a-tracking-plan).
+6. Once you've filled in the provided template or made changes to your downloaded Tracking Plan, add it to the upload field and click **Upload**.
+
+After uploading your CSV file, you are redirected to the Upload & Download History page while the upload is in progress. If the CSV upload fails due to issues with the content of your Tracking Plan, you can download the file `error_report.csv`, which provides you the error in the "Error Details" column of your CSV file. If the upload fails due to issues with the uploaded file itself (a file that is too large, has too many rows, or is not a CSV file, for example), you'll be able to view the error directly in the Reports column. 
+
+Common reasons a CSV upload may fail include: 
+- A filetype other than .csv
+- More than one file uploaded at a time
+- A file that is empty besides the header row
+- A CSV file that exceeds 100,000 rows
+- A CSV file with more than 20,000 rules
+- A CSV file with duplicate headers
+- A CSV file that is larger than 15 mb
+
+Any changes made to a Tracking Plan through an uploaded file are reflected in the [Tracking Plan changelog](/docs/protocols/faq/#how-can-i-see-who-made-changes-to-my-tracking-plan) and [Audit Trail](docs/segment-app/iam/audit-trail/).
+
 ### Remove a source from your Tracking Plan
 
 > info "Removing a source from a Tracking Plan requires Workspace Owner or Tracking Plan Admin permissions"