[hyperscript] rename decorators option in params to decorations (#2074)

#### Is this adding or improving a _feature_ or fixing a _bug_?

Debt.

#### What's the new behavior?

`createHyperscript` takes an options object that now looks for the `decorations` property instead of the `decorators` property

#### How does this change work?

Pretty straightforward rename of an option, then all of its uses and wherever the term decorators showed up in docs

#### Have you checked that...?

* [x] The new code matches the existing patterns and styles.
* [x] The tests pass with `yarn test`.
* [x] The linter passes with `yarn lint`. (Fix errors with `yarn prettier`.)
* [x] The relevant examples still work. (Run examples with `yarn watch`.)

#### Does this fix any issues or need any specific reviewers?

Fixes: #1996
Reviewers: @ianstormtaylor

packages/slate-hyperscript/test/decorations/across-blocks.js

@@ -6,7 +6,7 @@ const h = createHyperscript({
   blocks: {
     paragraph: 'paragraph',
   },
-  decorators: {
+  decorations: {
     highlight: 'highlight',
   },
 })

packages/slate-hyperscript/test/decorations/across-marks.js

@@ -9,7 +9,7 @@ const h = createHyperscript({
   marks: {
     b: 'bold',
   },
-  decorators: {
+  decorations: {
     highlight: 'highlight',
   },
 })

packages/slate-hyperscript/test/decorations/deep-anchors.js

@@ -7,7 +7,7 @@ const h = createHyperscript({
     ul: 'ul',
     li: 'li',
   },
-  decorators: {
+  decorations: {
     highlight: 'highlight',
   },
 })

packages/slate-hyperscript/test/decorations/intersecting-marks.js

@@ -9,7 +9,7 @@ const h = createHyperscript({
   marks: {
     b: 'bold',
   },
-  decorators: {
+  decorations: {
     highlight: 'highlight',
   },
 })

packages/slate-hyperscript/test/decorations/multiple.js

@@ -6,7 +6,7 @@ const h = createHyperscript({
   blocks: {
     paragraph: 'paragraph',
   },
-  decorators: {
+  decorations: {
     highlight: 'highlight',
     lowlight: 'lowlight',
   },

packages/slate-hyperscript/test/decorations/nested.js

@@ -6,7 +6,7 @@ const h = createHyperscript({
   blocks: {
     paragraph: 'paragraph',
   },
-  decorators: {
+  decorations: {
     highlight: 'highlight',
   },
 })

packages/slate-hyperscript/test/decorations/overlapping.js

@@ -6,7 +6,7 @@ const h = createHyperscript({
   blocks: {
     paragraph: 'paragraph',
   },
-  decorators: {
+  decorations: {
     highlight: 'highlight',
   },
 })

packages/slate-hyperscript/test/fixtures/decoration-across-blocks.js

@@ -6,7 +6,7 @@ const h = createHyperscript({
   blocks: {
     paragraph: 'paragraph',
   },
-  decorators: {
+  decorations: {
     highlight: 'highlight',
   },
 })

packages/slate-hyperscript/test/fixtures/decoration.js

@@ -6,7 +6,7 @@ const h = createHyperscript({
   blocks: {
     paragraph: 'paragraph',
   },
-  decorators: {
+  decorations: {
     highlight: 'highlight',
   },
 })