Batch elements and input widgets with st.form
Let's take a look at how to use st.form to batch elements and input widgets.
In Streamlit, every widget interaction causes a rerun of the app. However,
there are times when you might want to interact with a couple of widgets and
submit those interactions while triggering a single re-run of the app.
Using st.form you can batch input widgets together and along with
st.form_submit_button submit the state inside these widgets with the click
of a single button.
```python
Forms can be declared using the 'with' syntax
with st.form(key='my_form'):
    text_input = st.text_input(label='Enter your name')
    submit_button = st.form_submit_button(label='Submit')
```
```python
Alternative syntax, declare a form and use the returned object
form = st.form(key='my_form')
