basic_example_v1: move how-to-run.txt into README.md with syntax updates

Author: zinal

examples/basic_example_v1/how-to-run.txt renamed to examples/basic_example_v1/README.md

@@ -1,12 +1,13 @@
 Running this sample with the managed YDB instance in Yandex Cloud
-*********************************************************************************
+---
 
 (0) Install the yc command line tool
 https://cloud.yandex.ru/docs/cli/operations/install-cli
 
 (1) Create the service account using the YC Web Console, and assign it the ydb.editor role.
 Alternatively use the following shell snippet:
 
+```bash
 # Specify the Yandex Cloud folder and service account name
 export YC_FOLDER=mzinal
 export SA_NAME=ydb-sa-0
@@ -16,24 +17,33 @@ yc iam service-account create $SA_NAME
 export SA_ID=`yc iam service-account get --name $SA_NAME | sed -n 's/^id: \(.*\)$/\1/p'`
 # Assign the ydb.editor role for the specified YC folder to the service account just created
 yc resource-manager folder add-access-binding $YC_FOLDER --role ydb.editor --subject serviceAccount:$SA_ID 
+```
 
 (2) Generate the service account key to be used for authentication.
 Note: unfortunately, right now YC Web Console does not offer a way to generate the SA key
 with its Web interface.
 
+```bash
 yc iam key create --service-account-name $SA_NAME --output $HOME/key-ydb-sa-0.json
+```
 
 (3) Obtain the endpoint and database path from the Web Console.
-Alternatively, use the following command to grab it in the shell:
+Alternatively, use the following command to grab the required data in the shell:
 
-yc ydb db get --name ydb406
+```bash
+yc ydb db get --name ydb1
+```
+
+`ydb1` value in the command above is the logical name of the YDB managed database.
 
 (4) Run the sample:
 
+```bash
 # Set the path to the service account key file
 export YDB_SERVICE_ACCOUNT_KEY_FILE_CREDENTIALS=$HOME/key-ydb-sa-0.json
 # Set the database path and its endpoint
 export YDB_ENDPOINT=grpcs://ydb.serverless.yandexcloud.net:2135
 export YDB_DATABASE=/ru-central1/b1gfvslmokutuvt2g019/etnvbffeqegu1ub2rg2o
 # Run the script
 python3 __main__.py -e $YDB_ENDPOINT -d $YDB_DATABASE
+```