docs: modified sentence structure to improve clarity

docs/explanation/what_is_tp/index.qmd

@@ -44,7 +44,7 @@ Where:
 - $P_{access, i}$ is the total population that can travel to destination cell, $i$, within $t_{max}$ and $d_{max}$.
 - $P_{proxi, i}$ is the total population within $d_{max}$ of destination cell, $i$.
 
-This calculation is repeated across every destination cell within an urban centre, to produce transport performance heatmaps for an entire area of interest. An example of this for the [Newport, Wales urban centre] is shown in @fig-tp-newport.
+This calculation is repeated to construct the transport performance throughout an entire area of interest (in this case across every destination cell within the urban centre). An example of this for the Newport, Wales [urban centre] is shown in @fig-tp-newport.
 
 ::: {#fig-tp-newport layout-ncol="1"}
 
@@ -54,7 +54,7 @@ Transport performance across Newport, Wales. Public transit within 45 minutes. T
 
 :::
 
-@fig-tp-newport shows how transport performance can vary across an area on a granular scale. The yellow/light green region indicates that ~50-60% of the surrounding population can reach the main city centre of Newport, Wales using public transit within 45 minutes. The transport performance generally decreases closer to the outskirts of the urban centre. This means a smaller proportion of the surrounding population can reach the dark blue/purple areas using public transit within 45 minutes. Overall, it provides detailed, hyperlocal, insights into how the performance of the transport networks varies throughout an area.
+@fig-tp-newport shows how transport performance can vary across an area on a granular scale. The yellow/light green region indicates that ~50-60% of the surrounding population can reach the main city centre of Newport, Wales using public transit within 45 minutes. The transport performance also generally decreases closer to the outskirts of the urban centre. This means a smaller proportion of the surrounding population can reach the dark blue/purple areas using public transit within 45 minutes. Overall, it provides detailed, hyperlocal, insights into how the performance of the transport networks varies throughout an area.
 
 Calculating transport performance requires several stages of input data processing and transport network travel time estimation. The methods and tools used by this Python package are discussed in more detail on the [Transport Performance: An Overview](../calculate_tp/index.qmd) page. For more insights on how to use `transport_performance` itself, check out the [tutorials](../../tutorials/index.qmd) and [API reference](../../reference/index.qmd).