fix: sensible deposit and swap (#448)

* fix: indicate and lower minimum xdai to deposit

* fix: take user input on swap page

* fix: change minimum_dai to minimum_bzz

* fix: token naming convention

* refactor: use constants

* fix: check for positive decimal

src/components/SwarmTextInput.tsx

@@ -10,6 +10,7 @@ interface Props {
   formik?: boolean
   optional?: boolean
   defaultValue?: string
+  placeholder?: string
   onChange?: (event: ChangeEvent<HTMLTextAreaElement>) => void
 }
 
@@ -41,6 +42,7 @@ export function SwarmTextInput({
   formik,
   onChange,
   defaultValue,
+  placeholder,
 }: Props): ReactElement {
   const classes = useStyles()
 
@@ -57,6 +59,7 @@ export function SwarmTextInput({
         className={classes.field}
         defaultValue={defaultValue || ''}
         InputProps={{ disableUnderline: true }}
+        placeholder={placeholder}
       />
     )
   }
@@ -72,6 +75,7 @@ export function SwarmTextInput({
       defaultValue={defaultValue || ''}
       onChange={onChange}
       InputProps={{ disableUnderline: true }}
+      placeholder={placeholder}
     />
   )
 }