Discover docs updates for 9.0 (#943)

WIP
Discover-related changes for 9.0

- [x] Search sessions disabled by default (also updated settings in
elastic/kibana#216091, and mentioned in release
notes elastic/kibana#215772)
- [x] `Bytes` field renamed to `Bytes and Bits`

Author: florent-leborgne

explore-analyze/discover/search-sessions.md

@@ -8,10 +8,8 @@ mapped_pages:
 
 # Run a search session in the background [search-sessions]
 
-::::{admonition} Deprecated in 8.15.0.
-:class: warning
-
-Search Sessions are deprecated and will be removed in a future version.
+::::{admonition} Deprecated and disabled by default
+Search Sessions are deprecated. They are disabled by default and will be removed in a future version. You can enable search sessions again by setting [`data.search.sessions.enabled`](kibana://reference/configuration-reference/search-sessions-settings.md) to `true` in the `kibana.yml` configuration file.
 ::::
 
 

explore-analyze/find-and-organize/data-views.md

@@ -603,11 +603,11 @@ Supported transformations include:
 
 #### Number field formatters [field-formatters-numeric]
 
-Numeric fields support **Bytes**, **Color**, **Duration**, **Histogram**, **Number**, **Percentage**, **String**, and **Url** formatters.
+Numeric fields support **Bytes and Bits**, **Color**, **Duration**, **Histogram**, **Number**, **Percentage**, **String**, and **Url** formatters.
 
-The **Bytes**, **Number**, and **Percentage** formatters enable you to choose the display formats of numbers in the field using the [Elastic numeral pattern](../../explore-analyze/numeral-formatting.md) syntax that {{kib}} maintains.
+The **Bytes and Bits**, **Number**, and **Percentage** formatters enable you to choose the display formats of numbers in the field using the [Elastic numeral pattern](../../explore-analyze/numeral-formatting.md) syntax that {{kib}} maintains.
 
-The **Histogram** formatter is used only for the [histogram field type](elasticsearch://reference/elasticsearch/mapping-reference/histogram.md). When you use the **Histogram** formatter, you can apply the **Bytes**, **Number**, or **Percentage** format to aggregated data.
+The **Histogram** formatter is used only for the [histogram field type](elasticsearch://reference/elasticsearch/mapping-reference/histogram.md). When you use the **Histogram** formatter, you can apply the **Bytes and Bits**, **Number**, or **Percentage** format to aggregated data.
 
 You can specify the following types to the `Url` field formatter:
 

explore-analyze/numeral-formatting.md

@@ -57,9 +57,9 @@ The default percentage formatter in {{kib}} is `0,0.[000]%`, which shows up to t
 | -0.43 | 0 % | en (English) | -43 % |
 
 
-## Bytes and bits [_bytes_and_bits]
+## Bytes and Bits [_bytes_and_bits]
 
-The bytes and bits formatters will shorten the input by adding a suffix like `GB` or `TB`. Bytes and bits formatters include the following suffixes:
+The Bytes and Bits formatters will shorten the input by adding a suffix like `GB` or `TB`. Bytes and Bits formatters include the following suffixes:
 
 `b`
 :   Bytes with binary values and suffixes. 1024 = `1KB`