several topics fixes

Author: AndreiKingsley

docs/StardustDocs/topics/extensionPropertiesApi.md

@@ -147,7 +147,7 @@ df.filter { name.startsWith("A") && info.age >= 16 }
 Moreover, new extensions will be generated on-the-fly after each schema change: 
 by changing any column [name](rename.md),
 or [type](convert.md) or [add](add.md) a new one.
-For example, rename the "name" column into "firstName" and then we can use `firstName` extensions
+For example, rename the `name` column into "firstName" and then we can use `firstName` extensions
 in the following operations:
 
 ```kotlin

docs/StardustDocs/topics/guides/Guides-And-Examples.md

@@ -24,7 +24,7 @@ Explore our structured, in-depth guides to steadily improve your Kotlin DataFram
 
 <img src="quickstart_preview.png" border-effect="rounded" width="705"/>
 
-* [](extensionPropertiesApi.md) — learn about extension properties for `DataFrame` 
+* [](extensionPropertiesApi.md) — learn about extension properties for [`DataFrame`](DataFrame.md) 
 and make working with your data both convenient and type-safe.
 
 * [Enhanced Column Selection DSL](https://blog.jetbrains.com/kotlin/2024/07/enhanced-column-selection-dsl-in-kotlin-dataframe/)

docs/StardustDocs/topics/guides/quickstart.md

@@ -88,7 +88,7 @@ columns.
 Column selectors are widely used across operations — one of the simplest examples is `.select { }`, which returns a new
 DataFrame with only the columns chosen in Columns Selection expression.
 
-After executing the cell where a `DataFrame` variable is declared, 
+*After executing the cell* where a `DataFrame` variable is declared, 
 [extension properties](extensionPropertiesApi.md) for its columns are automatically generated.
 These properties can then be used in the Columns Selection DSL expression for typesafe and convenient column access.
 
@@ -111,13 +111,13 @@ dfSelected
 
 ## Row Filtering
 
-Some operations use [DataRow API](DataRow.md), with expressions and conditions 
+Some operations use the [DataRow API](DataRow.md), with expressions and conditions 
 that apply for all `DataFrame` rows.
-For example, `.filter { }` that returns a new `DataFrame` with rows \
-that satisfy a condition given by row expression.
+For example, `.filter { }` that returns a new `DataFrame` with rows that satisfy a condition given by row expression.
 
 Inside a row expression, you can access the values of the current row by column names through auto-generated properties.
-Similar to the Columns Selection DSL, but in this case the properties represent actual values, not column references.
+Similar to the [Columns Selection DSL](ColumnSelectors.md),
+but in this case the properties represent actual values, not column references.
 
 Filter rows by "stargazers_count" value: