doc: add initial staking section

pages/web/stake.mdx

@@ -1 +1,38 @@
 # Staking
+
+If you hold the staking token `UM` you can delegate, or stake, those tokens to a validator. This enables
+you to receive rewards and participate in governance in exchange for taking on the risk of validator misbehavior.
+
+To stake with Prax, first ensure you hold the Penumbra protocol's staking token `UM`.
+
+Next, select the `Stake` tab on your frontend.
+
+On the `Stake` tab, you can see how much `UM` you have available to delegate, along with a list of possible validators.
+For each validator, you will see some important data:
+
+* `VP`: the voting power of the validator in the governance system,
+* `Com`: the commission rate that validator takes.
+
+Once you select a validator to stake with, you can click the `Delegate` button.
+
+Select how much `UM` you wish to delegate, then press `Delegate`:
+
+<picture>
+  <img src="./images/delegation_amount_example.jpg" />
+</picture>
+
+It will take a few moments for the delegation transaction to be prepared, then Prax will generate a view of your
+transaction. Verify one of the outputs is to the validator you selected, then click `Approve`:
+
+<picture>
+  <img src="./images/delegation_prax.jpg" />
+</picture>
+
+You should see a pop-up in the lower right hand of the page indicating that the transaction was approved!
+
+<picture>
+  <img src="./images/delegation_popup.jpg" />
+</picture>
+
+You will receive the delegation token associated with that validator. At a later point, you can undelegate by clicking the `Undelegate` button
+to undelegate from that validator, and receive staking tokens.