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/styles/global.scss

@@ -81,14 +81,19 @@ p.flush {
   @include j40-element('sm', 4, 'normal', 0);
 }
 
+// 24 pixel margin-bottom
+.j40-mb-3 {
+  @include u-margin-bottom(3)
+}
+
 // 40 pixel margin-bottom
 .j40-mb-5 {
   @include u-margin-bottom(5)
 }
 
-// 24 pixel margin-bottom
-.j40-mb-3 {
-  @include u-margin-bottom(3)
+// 56 pixel margin-top
+.j40-mt-7 {
+  @include u-margin-top(7)
 }
 
 .j40-footer-ceq-font {

client/src/styles/theme/_uswds-theme-typography.scss

@@ -319,13 +319,13 @@ Or use `false` for unneeded weights.
 ----------------------------------------
 */
 
-$theme-font-weight-thin: false;
+$theme-font-weight-thin: 100;
 $theme-font-weight-light: 300;
 $theme-font-weight-normal: 400;
-$theme-font-weight-medium: false;
-$theme-font-weight-semibold: false;
+$theme-font-weight-medium: 500;
+$theme-font-weight-semibold: 600;
 $theme-font-weight-bold: 700;
-$theme-font-weight-heavy: false;
+$theme-font-weight-heavy: 800;
 
 // If USWDS is generating your @font-face rules,
 // should we generate all available weights