chore: import upstream snapshot with attribution

docs/md/explanation/table/update_and_remove.md

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+# `Table::update` and `Table::remove`
+
+Once a `Table` has been created, it can be updated with new data conforming to
+the `Table`'s schema. `Table::update` supports the same data formats as
+`Client::table`, minus _schema_.
+
+<div class="javascript">
+
+```javascript
+const schema = {
+    a: "integer",
+    b: "float",
+};
+
+const table = await perspective.table(schema);
+table.update(new_data);
+```
+
+</div>
+<div class="python">
+
+```python
+schema = {"a": "integer", "b": "float"}
+
+table = perspective.Table(schema)
+table.update(new_data)
+```
+
+</div>
+
+Without an `index` set, calls to `update()` _append_ new data to the end of the
+`Table`. Otherwise, Perspective allows
+[_partial updates_ (in-place)](#index-and-limit) using the `index` to determine
+which rows to update:
+
+<div class="javascript">
+
+```javascript
+indexed_table.update({ id: [1, 4], name: ["x", "y"] });
+```
+
+</div>
+<div class="python">
+
+```python
+indexed_table.update({"id": [1, 4], "name": ["x", "y"]})
+```
+
+</div>
+
+Any value on a `Client::table` can be unset using the value `null` in JSON or
+Arrow input formats. Values may be unset on construction, as any `null` in the
+dataset will be treated as an unset value. `Table::update` calls do not need to
+provide _all columns_ in the `Table`'s schema; missing columns will be omitted
+from the `Table`'s updated rows.
+
+<div class="javascript">
+
+```javascript
+table.update([{ x: 3, y: null }]); // `z` missing
+```
+
+</div>
+<div class="python">
+
+```python
+table.update([{"x": 3, "y": None}])  # `z` missing
+```
+
+</div>
+
+Rows can also be removed from an indexed `Table`, by calling `Table::remove`
+with an array of index values:
+
+<div class="javascript">
+
+```javascript
+indexed_table.remove([1, 4]);
+```
+
+</div>
+<div class="python">
+
+```python
+indexed_table.remove([1, 4])
+```
+
+</div>