Methodology page update for Score L (#1010)

* Add first column of Methodology score L

- create a new component MethodologyFormula (MF)
- MF component contain text on formula calculation
- add snapshots

* Add 2nd column to Methodology page

- add LowIncome component
- add USWDS styles on download component
- add margin-top styles to global
- enable all font-sizes to theme file

* Add Categories to Methodology page

- create CategoryCard component
- create Categories component
- add snapshots

* Update datasets

- update styling to match mock
- add additional indicators
- remove additional indicators
- update snapshots

* Add links to categories to datasets

- update snapshots

* Remove additional indicator test as they now N/A

* ensure each DOM ID is unique for a11y

- update snapshots

* Add Category heading for a11y

- removes ScoreSteps tests
- comment out ScoreStep component
- update snapshots
- cypress passes all a11y

* Update to methodology copy

- based on PDF and spreadsheet and Living Copy
-updates snapshots

* Add comments around using IF, AND, ELSE constants

- make indicator constant names more explicit

* Update copy based on living doc

- update snapshots

client/src/components/LowIncome/LowIncome.module.scss

@@ -0,0 +1,20 @@
+@use '../../styles/design-system.scss' as *;
+
+.lowIncomeContainer {
+
+    border: 1px solid #DFE1E2;
+    @include u-margin-top(4);
+    @include u-padding-left(4);
+    @include u-padding-right(3);
+    @include u-padding-bottom(4);
+
+    .lowIncomeTitle {
+        @include typeset('sans', 'xs', 3);
+        @include u-text('semibold');
+    }
+        
+    .lowIncomeText {
+        @include typeset('sans', 'xs', 3);
+        @include u-text('light');
+    }
+};