Docs: Minor edits to the README and several md files (#19238)

* Update README.md

Capitalized the G and S in "Getting Started," and moved "guide" to match the section title in the docs.

* Fixed sentence structure. Changed "download" to "grafana.com/get" and changed "get" to "download".

* Docs: Replace "datasources" with "data sources" (#19111)

* Docs: Replace "datasources" with "data sources" (#19111)

* Docs: Replace "datasources" with "data sources" (#19111)

* Docs: Replace "datasources" with "data sources" (#19111)

* Docs: Replace "datasources" with "data sources" (#19111)

* Docs: Replace "datasources" with "data sources" (#19111)

* Docs: Replace "datasources" with "data sources" (#19111)

* Docs: Replace "datasources" with "data sources" (#19111)

*  Docs: Replace "datasources" with "data sources" (#19111)

* Docs: Replace "datasources" with "data sources" (#19111)

* Docs: Replace "datasources" with "data sources" (#19111)

* Docs: Replace "datasources" with "data sources" (#19111)

docs/sources/features/panels/graph.md

@@ -38,7 +38,7 @@ Repeat a panel for each value of a variable.  Repeating panels are described in
 
 ## Metrics
 
-The metrics tab defines what series data and sources to render.  Each datasource provides different
+The metrics tab defines what series data and sources to render.  Each data source provides different
 options.
 
 ## Axes

docs/sources/features/panels/heatmap.md

@@ -60,9 +60,9 @@ Data format | Description
 
 ### Bucket bound
 
-When Data format is *Time series buckets* datasource returns series with names representing bucket bound. But depending
-on datasource, a bound may be *upper* or *lower*. This option allows to adjust a bound type. If *Auto* is set, a bound
-option will be chosen based on panels' datasource type.
+When Data format is *Time series buckets* data source returns series with names representing bucket bound. But depending
+on data source, a bound may be *upper* or *lower*. This option allows to adjust a bound type. If *Auto* is set, a bound
+option will be chosen based on panels' data source type.
 
 ### Bucket Size
 
@@ -77,9 +77,9 @@ If you have a data that is already organized into buckets you can use the `Time
 requires that your metric query return regular time series and that each time series has a numeric name that represent
 the upper or lower bound of the interval.
 
-There are a number of datasources supporting histogram over time like Elasticsearch (by using a Histogram bucket
+There are a number of data sources supporting histogram over time like Elasticsearch (by using a Histogram bucket
 aggregation) or Prometheus (with [histogram](https://prometheus.io/docs/concepts/metric_types/#histogram) metric type
-and *Format as* option set to Heatmap). But generally, any datasource could be used if it meets the requirements:
+and *Format as* option set to Heatmap). But generally, any data source could be used if it meets the requirements:
 returns series with names representing bucket bound or returns series sorted by the bound in ascending order.
 
 With Elasticsearch you control the size of the buckets using the Histogram interval (Y-Axis) and the Date Histogram interval (X-axis).

docs/sources/features/panels/table_panel.md

@@ -22,7 +22,7 @@ To view table panels in action and test different configurations with sample dat
 ## Querying Data
 
 The table panel displays the results of a query specified in the **Metrics** tab.
-The result being displayed depends on the datasource and the query, but generally there is one row per datapoint, with extra columns for associated keys and values, as well as one column for the numeric value of the datapoint.
+The result being displayed depends on the data source and the query, but generally there is one row per datapoint, with extra columns for associated keys and values, as well as one column for the numeric value of the datapoint.
 You can change the behavior in the section **Data to Table** below.
 
 ### Merge Multiple Queries per Table
@@ -35,7 +35,7 @@ In this example usage and capacity are metrics that will have corresponding data
 
 In its simplest case, both queries return time-series data with a numeric value and a timestamp.
 If the timestamps are the same, datapoints will be matched and rendered on the same row.
-Some datasources return keys and values (labels, tags) associated with the datapoint.
+Some data sources return keys and values (labels, tags) associated with the datapoint.
 These are being matched as well if they are present in both results and have the same value.
 The following datapoints will end up on the same row with one time column, two label columns ("host" and "job") and two value columns: