Fix typo's (#1136)

Costumer to Customer, costumer to customer

lnbits/extensions/offlineshop/README.md

@@ -6,9 +6,9 @@
 
 LNBits Offline Shop allows for merchants to receive Bitcoin payments while offline and without any electronic device.
 
-Merchant will create items and associate a QR code ([a LNURLp](https://github.com/lnbits/lnbits/blob/master/lnbits/extensions/lnurlp/README.md)) with a price. He can then print the QR codes and display them on their shop. When a costumer chooses an item, scans the QR code, gets the description and price. After payment, the costumer gets a confirmation code that the merchant can validate to be sure the payment was successful.
+Merchant will create items and associate a QR code ([a LNURLp](https://github.com/lnbits/lnbits/blob/master/lnbits/extensions/lnurlp/README.md)) with a price. He can then print the QR codes and display them on their shop. When a customer chooses an item, scans the QR code, gets the description and price. After payment, the customer gets a confirmation code that the merchant can validate to be sure the payment was successful.
 
-Costumers must use an LNURL pay capable wallet.
+Customers must use an LNURL pay capable wallet.
 
 [**Wallets supporting LNURL**](https://github.com/fiatjaf/awesome-lnurl#wallets)
 
@@ -18,18 +18,18 @@ Costumers must use an LNURL pay capable wallet.
    ![offline shop back office](https://i.imgur.com/Ei7cxj9.png)
 2. Begin by creating an item, click "ADD NEW ITEM"
    - set the item name and a small description
-   - you can set an optional, preferably square image, that will show up on the costumer wallet - _depending on wallet_
+   - you can set an optional, preferably square image, that will show up on the customer wallet - _depending on wallet_
-   - set the item price, if you choose a fiat currency the bitcoin conversion will happen at the time costumer scans to pay\
+   - set the item price, if you choose a fiat currency the bitcoin conversion will happen at the time customer scans to pay\
      ![add new item](https://i.imgur.com/pkZqRgj.png)
 3. After creating some products, click on "PRINT QR CODES"\
    ![print qr codes](https://i.imgur.com/2GAiSTe.png)
 4. You'll see a QR code for each product in your LNBits Offline Shop with a title and price ready for printing\
    ![qr codes sheet](https://i.imgur.com/faEqOcd.png)
 5. Place the printed QR codes on your shop, or at the fair stall, or have them as a menu style laminated sheet
-6. Choose what type of confirmation do you want costumers to report to merchant after a successful payment\
+6. Choose what type of confirmation do you want customers to report to merchant after a successful payment\
    ![wordlist](https://i.imgur.com/9aM6NUL.png)
 
-   - Wordlist is the default option: after a successful payment the costumer will receive a word from this list, **sequentially**. Starting in _albatross_ as costumers pay for the items they will get the next word in the list until _zebra_, then it starts at the top again. The list can be changed, for example if you think A-Z is a big list to track, you can use _apple_, _banana_, _coconut_\
+   - Wordlist is the default option: after a successful payment the customer will receive a word from this list, **sequentially**. Starting in _albatross_ as customers pay for the items they will get the next word in the list until _zebra_, then it starts at the top again. The list can be changed, for example if you think A-Z is a big list to track, you can use _apple_, _banana_, _coconut_\
      ![totp authenticator](https://i.imgur.com/MrJXFxz.png)
    - TOTP (time-based one time password) can be used instead. If you use Google Authenticator just scan the presented QR with the app and after a successful payment the user will get the password that you can check with GA\
      ![disable confirmations](https://i.imgur.com/2OFs4yi.png)

lnbits/extensions/satspay/README.md

@@ -18,7 +18,7 @@ Easilly create invoices that support Lightning Network and on-chain BTC payment.
      ![charge form](https://i.imgur.com/F10yRiW.png)
 3. The charge will appear on the _Charges_ section\
    ![charges](https://i.imgur.com/zqHpVxc.png)
-4. Your costumer/payee will get the payment page
+4. Your customer/payee will get the payment page
    - they can choose to pay on LN\
      ![offchain payment](https://i.imgur.com/4191SMV.png)
    - or pay on chain\

lnbits/extensions/tpos/README.md

@@ -11,5 +11,5 @@ An easy, fast and secure way to accept Bitcoin, over Lightning Network, at your
    ![create](https://imgur.com/8jNj8Zq.jpg)
 3. Open TPOS on the browser\
    ![open](https://imgur.com/LZuoWzb.jpg)
-4. Present invoice QR to costumer\
+4. Present invoice QR to customer\
    ![pay](https://imgur.com/tOwxn77.jpg)