Update README.md

Fix README markup

Author: vgvoleg

README.md

@@ -6,42 +6,44 @@ Python DBAPI to `YDB`, which provides both sync and async drivers and complies w
 
 ## Installation
 
-**TBD after first release**
+```shell
+pip install ydb-dbapi
+```
 
 ## Usage
 
 To establish a new DBAPI connection you should provide `host`, `port` and `database`:
 
-    ```python
-    import ydb_dbapi
+```python
+import ydb_dbapi
 
-    connection = ydb_dbapi.connect(
-        host="localhost", port="2136", database="/local"
-    ) # sync connection
+connection = ydb_dbapi.connect(
+    host="localhost", port="2136", database="/local"
+) # sync connection
 
-    async_connection = await ydb_dbapi.async_connect(
-        host="localhost", port="2136", database="/local"
-    ) # async connection
-    ```
+async_connection = await ydb_dbapi.async_connect(
+    host="localhost", port="2136", database="/local"
+) # async connection
+```
 
 Usage of connection:
 
-    ```python
-    with connection.cursor() as cursor:
-        cursor.execute("SELECT id, val FROM table")
+```python
+with connection.cursor() as cursor:
+    cursor.execute("SELECT id, val FROM table")
 
-        row = cursor.fetchone()
-        rows = cursor.fetchmany(size=5)
-        rows = cursor.fetchall()
-    ```
+    row = cursor.fetchone()
+    rows = cursor.fetchmany(size=5)
+    rows = cursor.fetchall()
+```
 
 Usage of async connection:
 
-    ```python
-    async with async_connection.cursor() as cursor:
-        await cursor.execute("SELECT id, val FROM table")
+```python
+async with async_connection.cursor() as cursor:
+    await cursor.execute("SELECT id, val FROM table")
 
-        row = await cursor.fetchone()
-        rows = await cursor.fetchmany(size=5)
-        rows = await cursor.fetchall()
-    ```
+    row = await cursor.fetchone()
+    rows = await cursor.fetchmany(size=5)
+    rows = await cursor.fetchall()
+```