chore: import upstream snapshot with attribution

docs/md/explanation/table/options.md

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+## Index and Limit
+
+<div class="warning">`limit` cannot be used in conjunction with `index`.</div>
+
+Initializing a `Table` with an `index` tells Perspective to treat a column as
+the primary key, allowing in-place updates of rows. Only a single column (of any
+type) can be used as an `index`. Indexed `Table` instances allow:
+
+-   In-place _updates_ whenever a new row shares an `index` values with an
+    existing row
+-   _Partial updates_ when a data batch omits some column.
+-   _Removes_ to delete a row by `index`.
+
+To create an indexed `Table`, provide the `index` property with a string column
+name to be used as an index:
+
+<div class="javascript">
+
+JavaScript:
+
+```javascript
+const indexed_table = await perspective.table(data, { index: "a" });
+```
+
+</div>
+<div class="python">
+
+Python
+
+```python
+indexed_table = perspective.Table(data, index="a");
+```
+
+</div>
+
+Initializing a `Table` with a `limit` sets the total number of rows the `Table`
+is allowed to have. When the `Table` is updated, and the resulting size of the
+`Table` would exceed its `limit`, rows that exceed `limit` overwrite the oldest
+rows in the `Table`. To create a `Table` with a `limit`, provide the `limit`
+property with an integer indicating the maximum rows:
+
+<div class="javascript">
+
+JavaScript:
+
+```javascript
+const limit_table = await perspective.table(data, { limit: 1000 });
+```
+
+</div>
+<div class="python">
+
+Python:
+
+```python
+limit_table = perspective.Table(data, limit=1000);
+```
+
+</div>